The genus Aloe needs no introduction — Aloe vera alone is one of the most recognisable plants on Earth, and the word “aloe” is embedded in cosmetics, medicine and popular culture worldwide. But behind the fame of that single species lies a group of astonishing diversity. The alooids — Aloe and its close relatives — comprise over seven hundred species of succulent plants, native to Africa, Madagascar and the Arabian Peninsula, ranging from tiny rosettes that fit in the palm of your hand to tree-like giants exceeding fifteen metres. They thrive in scorching deserts, cloud forests, coastal cliffs, high-altitude grasslands and tropical islands — a breadth of habitats that makes the alooids one of the most ecologically versatile groups of succulents on the planet.
For gardeners, aloes offer something agaves and cacti cannot: they flower reliably every year, in vivid colours — red, orange, yellow, coral, cream — without dying in the process. A mature Aloe ferox in bloom, its candelabra of scarlet spikes rising a metre above the rosette, is a spectacle that no garden should be without. And unlike agaves, aloes are polycarpic — they flower, survive and flower again, year after year, decade after decade.
This page is the reference for the genus Aloe on our site. It covers taxonomy, the recent reclassification that split the old genus into six genera, cultivation across different climates, and species selection — from windowsill miniatures to garden centrepieces. It also serves as the gateway to our detailed species profiles and thematic guides on aloe care, propagation and pest management.
Taxonomy and classification
Position in the plant kingdom
The genus Aloe was described by Carl Linnaeus in 1753 in the first edition of Species Plantarum. It belongs to the family Asphodelaceae, subfamily Asphodeloideae (formerly placed in Aloaceae or, more broadly, in Liliaceae). Its closest relatives are the genera Haworthia, Haworthiopsis, Gasteria, Astroloba, Tulista, Kniphofia and the recently segregated genera discussed below. Together, these genera form the group informally known as the alooids — a clade of approximately seven hundred species of succulent and semi-succulent plants, almost exclusively African in origin.
Aloes are not related to agaves, despite their superficial resemblance. Agaves belong to the family Asparagaceae (subfamily Agavoideae) and are native to the Americas. The similarity between the two groups — rosette growth form, succulent leaves, marginal teeth — is a textbook case of convergent evolution: two unrelated lineages independently evolving similar adaptations to arid environments on different continents.
The 2013–2014 reclassification: Aloe becomes six genera
For over two centuries, the genus Aloe was broadly circumscribed — any rosette-forming, succulent-leaved member of the family was placed in Aloe, from tiny stemless rosettes to massive tree-like species and scrambling climbers. By the early 2000s, molecular phylogenetic studies (using DNA sequence data) revealed that this broad concept of Aloe was not monophyletic — meaning it did not represent a single evolutionary lineage. Several groups within the old genus were more closely related to Haworthia or Gasteria than to each other.
In 2013 and 2014, Manning, Boatwright and colleagues (published in Systematic Botany, 2014) resolved this by dividing the old genus Aloe into six genera. A seventh, Aloestrela, followed in 2019 (Smith & Molteno, published in Bradleya). The reclassification was confirmed by a major phylogenomic study published by Woudstra et al. in 2025 (in Annals of Botany), which used nuclear genome sequencing to validate the monophyly of each segregated genus. The seven genera are:
Gonialoe — three species of small, distinctive aloes formerly placed in Aloe section Serrulatae. The best-known is Gonialoe variegata (formerly Aloe variegata, the partridge-breasted aloe or tiger aloe) — a compact species with beautifully banded leaves that is one of the most popular succulent houseplants worldwide.
Aloe sensu stricto — the “true aloes.” Over five hundred species remain in this genus after the segregation. These are the typical aloes: stemless or short-stemmed rosettes with succulent, usually toothed leaves and tubular flowers in racemes or panicles. All the most commonly cultivated species — Aloe vera, Aloe ferox, Aloe arborescens, Aloe maculata, Aloe polyphylla, Aloe marlothii, Aloe humilis, Aloe brevifolia, Aloe striata — remain in Aloe.
Aloidendron — the tree aloes. Six species of arborescent aloes that develop massive trunks and can reach ten to fifteen metres. The best-known are Aloidendron dichotomum (formerly Aloe dichotoma, the iconic quiver tree of Namibia), Aloidendron barberae (formerly Aloe barberae or Aloe bainesii, the largest of all aloes, reaching eighteen metres) and Aloidendron ramosissimum (formerly Aloe ramosissima). Tree aloes are spectacular in warm-climate gardens but are frost-tender and slow-growing.
Aloiampelos — the scrambling or rambling aloes. Shrubby plants with thin, slender stems that are often too weak to stand on their own and scramble through neighbouring vegetation. The most commonly cultivated are Aloiampelos ciliaris (formerly Aloe ciliaris, one of the fastest-growing of all aloes — an excellent covering plant for walls and fences) and Aloiampelos striatula (formerly Aloe striatula, one of the most cold-hardy of all aloe relatives — tolerating -10 °C or below in dry soil).
Aloestrela — a monotypic genus containing a single species: Aloestrela suzannae (formerly Aloe suzannae), endemic to the vanishing spiny forests of southern Madagascar. An unbranched, solitary succulent tree reaching about four metres — unique among all alooids for its nocturnal, fragrant flowers, presumably pollinated by bats. Plants take twenty to thirty years to reach flowering maturity and cannot be propagated vegetatively. The genus was erected by Smith & Molteno in 2019, six years after the initial reclassification. POWO and the CITES checklist accept it as valid, but molecular data (Malakasi et al. 2019) place Aloestrela suzannae as sister to Aloidendron eminens within the Aloidendron clade — its generic status remains debated. Endangered on the IUCN Red List.
Aristaloe — a monotypic genus containing a single species: Aristaloe aristata (formerly Aloe aristata, the lace aloe or torch plant). This compact, heavily textured species looks more like a large Haworthia than a typical aloe — and molecular studies confirm it is indeed more closely related to the haworthioid group than to true aloes. It is one of the hardiest “aloes” in cultivation, tolerating -10 °C or below, and is an excellent pot plant.
Kumara — two species of distinctive fan-leaved aloes from the Western Cape of South Africa. Kumara plicatilis (formerly Aloe plicatilis) is the famous fan aloe — unique among all aloe relatives for its distichous (fan-shaped) leaf arrangement. A mature Kumara plicatilis with its architectural fans of grey-green leaves atop a forked trunk is one of the most photogenic succulents in the world. The second species is Kumara haemanthifolia.
What this means for gardeners
In practical terms, the reclassification changes names but not growing conditions. An Aloiampelos striatula is the same plant as the Aloe striatula you have been growing — it just has a new genus name. Nurseries and garden centres are slow to adopt the new names, so you will encounter both old and new nomenclature for years to come. On our site, we use the currently accepted names following POWO (Plants of the World Online, maintained by Kew), with the former Aloe names noted as synonyms on each species profile.
Distribution and diversity
Aloes (in the broad sense, including all six genera) are native to the Old World — Africa, Madagascar and the Arabian Peninsula. The centre of diversity is South Africa, which hosts the greatest number of species — from the winter-rainfall deserts of the Western Cape to the subtropical forests of KwaZulu-Natal, the high-altitude grasslands of the Drakensberg and the arid Karoo. East Africa (Kenya, Tanzania, Ethiopia) is a secondary centre of diversity, with many endemic species in the montane and coastal zones. Madagascar hosts a distinct radiation of aloes, many of which are found nowhere else.
Aloe vera, the most commercially important species, has been cultivated for so long that its precise wild origin is debated — recent evidence points to the Arabian Peninsula, but it has been naturalised across the tropics for millennia.
The aloes you see growing “wild” around the Mediterranean — in Spain, Portugal, Italy, Greece, southern France — are all introductions. Aloe arborescens, Aloe maculata and Aloe vera have naturalised widely in Mediterranean climates and can appear genuinely wild, but they are not native to Europe.
Morphology: what makes an aloe an aloe
Leaves: succulent, typically arranged in a rosette, lanceolate (sword-shaped), usually with marginal teeth (but not always — some species are smooth-margined). The leaf surface can be smooth, tuberculate, spotted or banded. Leaf colour ranges from bright green through blue-grey to almost white. Inside the leaf, a clear gel (in many species) and a bitter yellow exudate (aloin) are present — the gel is the basis of the enormous Aloe vera industry.
Flowers: tubular, arranged in racemes or panicles on a stalk (peduncle) that rises above the rosette. Flower colour is typically red, orange, yellow or cream — occasionally bicoloured. Most species flower in winter or early spring (in the Southern Hemisphere), making them valuable garden plants during a season when few other succulents bloom. Pollination is primarily by sunbirds (in Africa), bees and other insects.
Growth forms: stemless rosettes (the majority), short-stemmed rosettes, tall-stemmed single-trunked forms, multi-branched shrubs (now in Aloiampelos) and massive trees (now in Aloidendron). Some species sucker prolifically from the base, forming dense clumps; others remain solitary throughout their lives.
Cultivation: the fundamentals
Aloes are among the easiest succulents to grow — provided you respect three non-negotiable requirements.
1. Excellent drainage. Like all succulents, aloes store water in their leaves and are adapted to survive long dry periods. Wet roots — particularly in cool weather — are the number one killer. In the ground, plant in sandy, gravelly or rocky soil. In heavy clay, build a raised bed with mineral substrate. In pots, use a mix of 50–60 % mineral material (pumice, perlite, coarse sand) and 40–50 % potting compost or coco coir. The substrate must drain in seconds.
2. Bright light. Most aloes need full sun or very bright indirect light. In shade, rosettes etiolate — they become open, leggy and pale. A few species (Aloe humilis, Aristaloe aristata, some Madagascan species) tolerate partial shade, but even these perform better with strong light. Indoors, a south-facing window is the minimum.
3. Moderate water — less is better. Water deeply when the substrate is dry, then let it dry out completely before watering again. In summer, this means every one to three weeks depending on conditions. In winter, reduce to once a month or less — many species need almost no water during their dormant period. Overwatering in winter is the classic path to root rot.
Frost hardiness
Most aloes are significantly less cold-hardy than agaves. The majority of species are damaged at or below -2 °C and killed at -5 °C. However, a handful of species tolerate genuine frost:
Aloiampelos striatula (formerly Aloe striatula) — the hardiest of all aloe relatives, tolerating -10 °C or even lower in dry soil. A scrambling, shrubby species from the high-altitude Eastern Cape. Excellent for cold-climate gardens where no true aloe would survive.
Aristaloe aristata (formerly Aloe aristata) — hardy to approximately -10 °C. A compact, highly textured rosette. One of the best “aloes” for zones 8 and colder.
Aloe polyphylla — the spiral aloe from the high Drakensberg of Lesotho. Hardy to approximately -7 °C in dry, well-drained soil. A legendary species whose perfect Fibonacci spiral of leaves makes it one of the most coveted plants in the world. It is, however, notoriously difficult to cultivate in warm, humid climates — it prefers cool, dry conditions.
Aloe brevifolia — hardy to approximately -5 °C. A compact, blue-grey species from the Western Cape.
Aloe maculata (formerly Aloe saponaria) — hardy to approximately -5 °C. A vigorous, suckering species with spotted leaves. One of the most commonly planted aloes in Mediterranean gardens.
Aloe arborescens — hardy to approximately -4 °C. The “krantz aloe” — a large, shrubby species that flowers spectacularly in midwinter with scarlet spikes. Widely naturalised in Mediterranean climates.
For detailed frost hardiness information and species recommendations by USDA zone, see our guide to cold-hardy aloes (forthcoming).
Growing aloes around the world
The Mediterranean Basin. The perfect climate for most aloes. Hot, dry summers and mild, wet winters suit the majority of South African and East African species. Aloe arborescens, Aloe maculata and Aloe vera have naturalised widely along the coasts of Spain, Italy, southern France, Greece and Turkey. In these regions, aloes grow in the ground with zero supplemental irrigation — natural rainfall is more than sufficient. The main risk is exceptional frost events: a rare -8 °C in the French Riviera or Andalusia can devastate collections of tender species. Choose the hardier species for permanent planting and keep rare, tender specimens in containers that can be moved under cover.
The southwestern United States and California. Aloe paradise. Southern California — from Santa Barbara to San Diego — has conditions virtually identical to the Western Cape of South Africa, and aloes thrive here with minimal care. The water-wise landscaping movement has driven a surge in aloe planting, replacing thirsty lawns with drought-tolerant succulent gardens. Arizona and the desert Southwest are too hot and too dry for most aloes (they are adapted to winter rainfall, not summer aridity), but irrigated desert gardens can grow them successfully.
The United Kingdom and northern Europe. Too cold and too wet for most aloes in the ground. Container culture with indoor wintering is the standard approach. A few tough species — Aloiampelos striatula, Aristaloe aristata, Aloe polyphylla (in very well-drained raised beds) — can survive outdoors in the mildest microclimates of Cornwall, the Channel Islands and the Irish coast. For everyone else: pots, a sunny terrace in summer, and a bright, cool room in winter.
Australia. Excellent growing conditions across most of the continent. Aloes have naturalised in parts of eastern Australia (particularly Aloe maculata and Aloe arborescens) and are widely planted in water-wise gardens. The dry-summer, mild-winter climate of coastal southern Australia is ideal. In tropical northern Australia, some aloes struggle with humidity and wet summers — drainage becomes even more critical.
Container culture
Containers are the key to growing aloes in any climate. A potted aloe spends summers outdoors in full sun, growing vigorously and flowering, and winters in a bright, frost-free room where it rests. The principles are identical to those for container cycads and agaves: mineral-heavy substrate (50–60 % pumice or perlite), terracotta or resin pots with drainage holes, deep watering when dry, and almost no water in winter.
For a diverse aloe collection, containers are not a compromise — they are an advantage. You can tailor the substrate, watering and exposure to each species individually. A tender Aloidendron dichotomum seedling, a hardy Aristaloe aristata and a tropical Aloe polyphylla can all coexist in your collection, each in its own optimised pot.
A seasonal care calendar
Spring (March–May): resume watering as temperatures rise. This is the best time to repot, divide offsets and start seed. Watch for new root growth and the first signs of flower buds forming in early-blooming species.
Summer (June–August): the active growing season. Water deeply when dry — typically every seven to fourteen days for potted aloes in full sun. Move indoor aloes outside. Apply a single dose of balanced, slow-release fertiliser. This is when most aloes produce their annual flush of new leaves.
Autumn (September–November): reduce watering progressively. Bring tender container aloes indoors before the first frost. In the ground, ensure drainage is optimal before the wet season begins. Many South African species begin to form flower buds in autumn — their flowering season is winter.
Winter (December–February): the flowering season for many aloes (following the Southern Hemisphere rhythm even in the Northern Hemisphere). Water minimally — once a month or less for potted aloes indoors. Do not fertilise. Enjoy the flowers — in mild climates, Aloe arborescens and Aloe ferox produce their spectacular spikes during the coldest months, bringing vivid colour to the winter garden.
Indoor cultivation
Aloes are among the most successful indoor succulents — provided they receive enough light. A south-facing window is ideal. The most commonly grown indoor species are Aloe vera (the most popular), Gonialoe variegata (formerly Aloe variegata — tolerates lower light than most), Aristaloe aristata (compact, textured, very hardy) and Aloe humilis (a compact, suckering species with white-spotted leaves).
Indoors, the biggest risk is overwatering in low light. The combination of warm room temperatures and insufficient sun produces soft, etiolated growth that is vulnerable to rot. Water sparingly — every three to four weeks in winter — and move the plant outdoors for the summer whenever possible.
Propagation
From offsets (pups): the easiest method. Many aloes sucker prolifically, producing basal offsets that can be detached with a sharp knife, allowed to dry for a few days, and planted in well-drained substrate. Best done in spring or early summer.
From leaf cuttings: possible for some species (notably Aloe vera) but unreliable. Aloe leaves can rot before rooting. Offsets are always preferable when available.
From seed: aloe seeds germinate readily at 20–25 °C on a moist, well-drained substrate. Germination occurs within one to four weeks. Seedlings are slow-growing but reach flowering size in three to five years for most species. Seed-raised plants are genetically diverse — important for conservation and for producing novel colour forms.
Pests and diseases
Mealybugs: the most common pest. White cottony masses at leaf bases. Treatment: isopropyl alcohol for light infestations, neem oil for heavier ones.
Aloe mite (Aceria aloinis): a microscopic eriophyid mite that causes abnormal tissue growths (galls) on the leaves, flowers and stems. Infested tissue must be removed and destroyed. There is no effective chemical treatment — prevention (quarantine of new plants) is essential.
Aloe rust: a fungal disease causing raised brown or black spots on the leaves. Usually cosmetic rather than fatal. Improve air circulation and reduce overhead watering.
Root rot (Phytophthora, Fusarium): caused by wet substrate, poor drainage and overwatering — especially in cool weather. Prevention is the only reliable strategy: excellent drainage, correct watering, mineral mulch at the base.
Aloe thrips (Hercinothrips dimidiatus): a South African thrips spreading across Mediterranean Europe, causes silvery scarring and progressive blackening that can kill aloes.
Aloes in human culture
Aloe vera — the medicinal and cosmetic giant. The clear gel from Aloe vera leaves is one of the most widely used natural ingredients in the world — valued for moisturising, soothing burns, wound healing and skin care. The global Aloe vera industry is worth billions of dollars annually. The gel is harvested commercially in Mexico, the Dominican Republic, India, Thailand and many other tropical countries.
Aloe ferox — the bitter aloe. The bitter yellow exudate (aloin) from the leaf skin of Aloe ferox has been used medicinally in southern Africa for centuries — as a purgative, wound treatment and general tonic. A. ferox is still harvested commercially in the Eastern Cape and Western Cape of South Africa, where wild-harvested aloe products are a significant source of rural income.
Ornamental use. Aloes are among the most widely planted succulents worldwide — in Mediterranean gardens, arid landscapes, coastal plantings, public spaces and indoor collections. Their winter-flowering habit (in the Southern Hemisphere cycle) makes them particularly valuable in regions where few other plants bloom from November to February.
Choosing aloes for your garden
For a bold garden statement
Aloe ferox — a large, single-stemmed species with a dramatic crown of thick, spiny leaves and spectacular scarlet flower spikes in winter. Hardy to approximately -3 °C. The definitive aloe for a Mediterranean garden.
Aloe marlothii — similar in stature to A. ferox but with broader leaves and horizontal flower racemes. Hardy to approximately -3 °C. Magnificent as a specimen or in groups.
Aloe arborescens — a large, shrubby species that can reach three to four metres. Brilliant scarlet winter flowers. Hardy to approximately -4 °C. Outstanding as a hedge or screen in frost-free gardens.
For containers and small gardens
Aloe humilis — compact, suckering, white-spotted. Hardy to approximately -5 °C. Excellent in small pots and rock gardens.
Aloe brevifolia — compact, blue-grey, densely suckering. Hardy to approximately -5 °C. A classic pot aloe.
Aristaloe aristata — compact, heavily textured, very hardy (to -10 °C). Thrives in pots and tolerates lower light than most aloes.
Gonialoe variegata — the tiger aloe. Compact, beautifully banded. Tolerates low light — one of the best aloes for indoor culture.
For ground cover and mass planting
Aloe maculata — vigorous, suckering, spotted leaves. Hardy to approximately -5 °C. Produces dense carpets of rosettes and flowers prolifically in coral-orange. One of the most widely planted aloes in Mediterranean landscapes.
Aloe striata — the coral aloe. Smooth, unspotted, blue-grey leaves with a pink margin. Hardy to approximately -4 °C. Stunning in groups.
For cold climates (USDA zones 7–8)
Aloiampelos striatula — the only aloe relative reliably hardy in zone 7. Scrambling habit, can be trained against a wall. Hardy to -10 °C.
Aristaloe aristata — hardy to -10 °C. The best compact “aloe” for cold gardens.
For collectors
Aloe polyphylla — the spiral aloe. Hardy to -7 °C but needs cool, dry conditions — it dislikes hot, humid summers. A challenge, but the reward is one of the most extraordinary plants on Earth. The Fibonacci spiral of its 150+ leaves, visible from above, is one of the most perfect geometric patterns in the plant kingdom. From the high Drakensberg of Lesotho, at altitudes of 2,000 to 2,500 metres, where it experiences snow, frost and intense UV radiation — a very different environment from most aloes.
Kumara plicatilis — the fan aloe. Hardy to approximately -3 °C. Unique distichous leaf arrangement — the only aloe relative with fan-shaped leaves. A mature specimen with forked branches, each tipped with a grey-green fan of succulent leaves, is unlike any other plant in the world. Native to the fynbos of the Western Cape. Slow-growing but worth every year of patience.
Aloidendron dichotomum — the quiver tree. Frost-tender but an extraordinary specimen for warm-climate gardens. The forked, corky trunk crowned with rosettes is an icon of the Namibian landscape. Named for the practice of the San people, who hollowed out the branches to make quivers for their arrows. Can reach six to nine metres in cultivation over many decades.
Aloe speciosa — the tilt-head aloe. A single-stemmed species from the Eastern Cape whose rosette tilts dramatically to one side, always facing north in the Southern Hemisphere (and south in the Northern). The flower spikes are dense, cylindrical and vivid red-orange. A mature specimen with its characteristic lean is one of the most photogenic aloes.
Aloe thraskii — a large, single-trunked species from the KwaZulu-Natal coast. Gracefully recurved leaves and a stately trunk to four metres. Hardy to approximately -2 °C. One of the most elegant aloes for a subtropical garden.
Hybridisation
Aloes hybridise readily — both in the wild (where species ranges overlap) and in cultivation. The result is an enormous and ever-expanding range of hybrid cultivars, many of which combine the best qualities of their parents: compact size, vivid flower colour, vigour and drought tolerance. Some of the most popular garden aloes are hybrids — the ‘Hedgehog’ hybrids, the ‘Safari’ series and dozens of unnamed crosses between Aloe arborescens, Aloe ferox, Aloe maculata and other vigorous species.
Intergeneric hybrids are also possible within the alooid group — crosses between Aloe and Gasteria (×Gasteraloe), between Aloe and Haworthia, and between Gasteria and Haworthia (×Gasterhaworthia) have all been produced. These hybrids are often attractive, compact and easy to grow — and they blur the already fuzzy boundaries between genera in this closely related group.
For collectors, hybridisation is both an opportunity and a caution. Named hybrid cultivars from reputable nurseries are desirable garden plants. But the ease of hybridisation means that aloes grown from garden-collected seed may be hybrids rather than pure species — important to keep in mind if taxonomic accuracy matters to you.
Horticole hybrids of aloes
Aloe × nobilis — An ancient hybrid of uncertain parentage, probably Aloe mitriformis × Aloe brevifolia. Compact, bright green rosettes with conspicuous golden marginal teeth. Prolifically suckering. Parent of the ubiquitous ‘Crosby’s Prolific.’ Hardy to –6 °C.
Aloe x spinosissima — a garden hybrid (or natural form, with origin debated) with heavily toothed leaves and red flowers. Hardy to -5 °C.
Aloidendron ‘Hercules’ — hybrid of Aloidendron barberae and Aloidendron dichotomum, is the most widely planted tree aloe in Californian and Mediterranean landscapes. Hardy to -5 °C.
Aloe vs Agave: how to tell them apart
Despite looking similar at a glance, aloes and agaves are easy to distinguish once you know the key differences. Aloes are African, polycarpic (they flower every year and survive), with softer leaves containing a clear gel. Agaves are American, monocarpic (they flower once and die), with rigid, fibrous leaves and an irritant sap. An aloe treated like an agave — kept too dry, in too-poor soil — will sulk. An agave treated like an aloe — watered frequently, in rich soil — will rot. For a detailed comparison, see our guide to the differences between aloes and agaves.
Species list: commonly cultivated aloes and allied genera
The genus Aloe sensu stricto contains over five hundred accepted species. The following list covers the species most commonly encountered in cultivation, organised by geographic origin — reflecting the strong geographic structure revealed by recent phylogenomic studies (Grace et al. 2015, Woudstra et al. 2025). Within each region, species are grouped by taxonomic section (Berger 1908, amended by Reynolds 1950 and Glen & Hardy 2000) where these sections correspond to well-supported phylogenomic clades. The segregated genera (Aloidendron, Aloiampelos, Aristaloe, Kumara, Gonialoe) are listed separately at the end.
Southern Africa (~170 species) — the oldest and most diverse radiation
The phylogenetically oldest clades in the genus are predominantly southern African. Many of the sections defined by Berger (1908) — the earliest comprehensive infrageneric classification — are confirmed as monophyletic by modern molecular studies.
Section Pachydendron — the single-stemmed tree aloes. Large, solitary rosettes on thick trunks, typically with a candelabra-shaped inflorescence. The most spectacular garden aloes for warm climates.
Aloe ferox — Eastern and Western Cape. The bitter aloe. Trunk to 3–5 m, robust spiny leaves, spectacular scarlet winter flowers. Hardy to -3 °C. Commercially harvested for aloin.
Aloe marlothii — Limpopo, Mpumalanga, KwaZulu-Natal, extending into Mozambique, Zimbabwe and Swaziland. Massive, with distinctive horizontal flower racemes. Hardy to -3 °C. One of the most imposing aloes in cultivation.
Aloe speciosa — Eastern Cape. The tilt-head aloe. Rosette tilts toward the equator. Dense cylindrical red-orange spikes. Hardy to -3 °C.
Aloe thraskii — KwaZulu-Natal coast. Gracefully recurved leaves, elegant stature to 4 m. Hardy to -2 °C.
Aloe africana — Eastern Cape (Port Elizabeth to Grahamstown). Slender trunk, narrow leaves, yellow flower spikes. Hardy to -3 °C.
Aloe spicata — Limpopo, Mpumalanga. Tall-stemmed, cylindrical yellow-orange spikes. Hardy to -2 °C.
Aloe excelsa — Zimbabwe, Mozambique, northern South Africa. One of the tallest aloes — trunk to 5 m. Open crown with broad leaves. Red flower racemes. Hardy to -2 °C.
Aloe candelabrum — KwaZulu-Natal. Similar to A. ferox but with more recurved leaves and a distinctive candelabra-shaped inflorescence. Hardy to -3 °C. Sometimes treated as a synonym or variety of A. ferox.
Aloe castanea — Limpopo. A tall-stemmed species with distinctive brownish-orange flower spikes. Hardy to -2 °C.
Aloe alooides — Mpumalanga, Limpopo. A slender-trunked species with narrow, grassy leaves and long cylindrical flower racemes. Hardy to -3 °C.
Section Aloe — a basal, early-diverging clade of southern African aloes, sister to the rest of the genus.
Aloe arborescens — widespread across southern and eastern Africa. The krantz aloe. Large, branching shrubs to 3–4 m. Brilliant scarlet winter spikes. Hardy to -4 °C. Widely naturalised in Mediterranean climates. One of the most cold-hardy true aloes.
Aloe pluridens — Eastern Cape, KwaZulu-Natal. A tall, multi-stemmed species forming dense clumps. Trunk to 3–5 m. Red-orange flowers. Hardy to -3 °C. An excellent screening plant.
Aloe mutabilis — Limpopo, Mpumalanga. Variable species, often shrubby. Bicoloured flowers (yellow and red on the same raceme). Hardy to -2 °C.
Section Pictae — the maculate (spotted) aloes. Rosettes often flat to the ground, leaves typically spotted with pale markings, flowers in branched panicles.
Aloe maculata (syn. Aloe saponaria) — widespread across southern Africa. The most commonly planted aloe in Mediterranean landscapes. Vigorous, suckering, spotted leaves, coral-orange flowers. Hardy to -7 °C.
Aloe grandidentata — Eastern Cape, Free State. Spotted leaves with prominent marginal teeth. Hardy to -5 °C.
Aloe zebrina — Botswana, Zimbabwe, Mozambique, northern South Africa. Strongly banded leaves, beautiful ground cover. Hardy to -3 °C.
Aloe pratensis — Eastern Cape, Free State (high-altitude grasslands). Compact, spotted rosettes. Hardy to -7 °C. One of the hardier spotted aloes.
Aloe greatheadii — widespread across the Highveld of South Africa, Botswana, Zimbabwe. Flat rosettes with heavily spotted leaves. Hardy to -8 °C. One of the most widely distributed maculate aloes.
Aloe parvibracteata — KwaZulu-Natal, Mpumalanga. Spotted leaves, branched inflorescences with small bracts. Hardy to -4 °C.
Aloe microstigma — Western Cape, Eastern Cape. Compact, heavily spotted, prolific flowers. Hardy to -4 °C.
Aloe davyana — Gauteng, Mpumalanga, Limpopo. A common Highveld maculate aloe. Spotted leaves, branched panicles. Hardy to -5 °C.
Section Leptoaloe — the grass aloes. Small, often stemless, narrow-leaved, occurring in grasslands. The youngest major radiation, diversifying within the last ~10 million years.
Aloe cooperi — KwaZulu-Natal. Grass-like leaves, orange-red flowers. Hardy to -5 °C. Good for meadow-style planting.
Aloe ecklonis — Eastern Cape, KwaZulu-Natal. Slender, bulbous base. Hardy to -5 °C.
Aloe linearifolia — KwaZulu-Natal (high altitude grasslands). Very narrow, grass-like leaves. Hardy to -5 °C.
Aloe kraussii — KwaZulu-Natal. A tiny grass aloe, barely ten centimetres tall. Yellow flowers. Hardy to -5 °C.
Aloe minima — KwaZulu-Natal, Eastern Cape. One of the smallest aloes — rosettes to five centimetres. Hardy to -5 °C. Curiosity for collectors.
Section Breviflorae
Aloe brevifolia — Western Cape. Compact, blue-grey, densely suckering rosettes. Hardy to -5 °C. A classic container aloe.
Section Humiles
Aloe humilis — Eastern and Western Cape. Compact, heavily white-spotted. Hardy to -5 °C. Excellent in small pots.
Aloe broomii — widespread across South Africa (semi-arid regions). Compact, dark green, with a distinctive leaf rosette enclosing the inflorescence. Hardy to -7 °C.
Aloe longistyla — Western Cape (Little Karoo). Short rosettes with very long, protruding flower styles — an unusual floral character. Hardy to -5 °C.
Section Striatae
Aloe striata — Eastern and Western Cape. The coral aloe. Smooth, blue-grey, unspotted leaves with a pink or red margin. No marginal teeth — one of the few smooth-leaved aloes. Flat, branched coral-pink inflorescences. Hardy to -4 °C. Stunning in groups.
Aloe karasbergensis — Namibia (Karas Mountains). Similar to A. striata but smaller and more compact. Hardy to -5 °C.
Section Mitriformes
Aloe mitriformis (syn. Aloe perfoliata) — Western Cape. Procumbent, suckering, blue-green. Dense scarlet conical flower heads. Hardy to -4 °C. Good ground cover.
Aloe distans — Western Cape. A prostrate, creeping species with triangular blue-green leaves. Dense red flower heads. Hardy to -4 °C. Excellent ground cover and cascading plant.
Aloe comptonii — Western Cape. Sprawling, blue-green rosettes with prominent white teeth. Red flowers. Hardy to -4 °C.
Section Ortholophae
Aloe claviflora — Northern Cape, Free State. A distinctive stemless species with club-shaped (clavate) red flowers on a horizontal inflorescence. Hardy to -7 °C. One of the hardiest true aloes.
Aloe globuligemma — Northern Cape. Stemless, with globular red flower buds. Hardy to -6 °C.
Aloe falcata — Northern Cape. Low, clumping rosettes with sickle-shaped bluish leaves and multi-branched brick-red flower spikes. The only Karoo aloe that flowers in midsummer. Hardy to -5 °C.
Section Dracoaloe (partially — some species now in Aloidendron)
Aloe rupestris — KwaZulu-Natal, Mpumalanga. A tall-stemmed tree aloe (within Aloe sensu stricto, not Aloidendron). Trunk to 8 m. Hardy to -3 °C.
Other southern African species in cultivation
Aloe polyphylla — Lesotho (Drakensberg, 2,000–2,500 m). The spiral aloe. Hardy to -7 °C. The famous Fibonacci spiral rosette — one of the most extraordinary plants on Earth. Requires cool, dry conditions; struggles in hot, humid climates.
Aloe reitzii — Mpumalanga. A tall-stemmed, striking species with dense red flower spikes. Hardy to -7 °C.
Aloe kedongensis — Kenya (Rift Valley). A shrubby species with narrow leaves. Hardy to -2 °C.
Aloe glauca — Western Cape. Compact rosettes of blue-grey leaves with white marginal teeth. Hardy to -3 °C.
Aloe melanacantha — Northern Cape, Namibia. Compact, dark-spined, very ornamental. Hardy to -5 °C. A collector’s favourite.
Aloe erinacea — Namibia (Fish River Canyon area). A small, densely spined species — known as the “goree” aloe. Very slow-growing, extremely ornamental. Hardy to -3 °C in dry soil.
Aloe chlorantha — Western Cape (Namaqualand). A winter-rainfall species with green-tipped yellow flowers. Hardy to -8 °C.
Aloe dichotoma — see Aloidendron dichotomum below.
East Africa and the Zambezian region (~100 species)
A younger radiation than the southern African clades, diversifying over the last ~10 million years. Molecular studies show that tropical African aloes are better characterised by geographic distribution than by morphology — traditional sections based on leaf and flower form do not always correspond to evolutionary lineages.
Kenya and Tanzania — the East African savanna and mountain radiation
Aloe secundiflora — Kenya, Tanzania. Common in East African savanna. Orange-red, one-sided flower racemes. A keystone species in dry-land ecosystems — the shrubs create microhabitats that improve soil conditions and encourage the growth of surrounding vegetation. Hardy to -2 °C.
Aloe lateritia — East Africa (Kenya to Mozambique). Variable, suckering, often spotted. One of the most widespread East African aloes, found from sea level to 2,500 m. Hardy to -2 °C.
Aloe dorotheae — Tanzania (a single locality near Dodoma). Small rosettes that turn brilliant red in drought stress — one of the most dramatic colour changes in the genus. Rare and endangered in the wild, but increasingly available from specialist nurseries. Tender.
Aloe elgonica — Kenya (Mount Elgon, high altitude). A robust mountain aloe with broad, grey-green leaves and branched orange inflorescences. Hardy to -3 °C.
Aloe volkensii — Kenya, Tanzania. A tall-stemmed species common in open woodland and along the Rift Valley escarpment. Trunk to 4 m, simple or sparsely branched. Orange-red flowers. Hardy to -2 °C.
Aloe rabaiensis — Kenya (coastal lowlands near Mombasa). Stemless to short-stemmed, suckering, coral-red flowers. Grows on coral limestone and sandy soils in hot, humid coastal bush. Tender.
Aloe ballyi — Kenya, Tanzania. A tall, slender species with an elegant trunk and red flowers. The inflorescence is distinctively elongated and rat-tail-like — one of the most unusual floral forms in the genus. Tender.
Aloe nyeriensis — Kenya (Mount Kenya foothills, Nyeri area). A robust, spotted species with broad leaves and branched inflorescences of red-orange flowers. One of the more ornamental East African aloes. Hardy to -2 °C.
Aloe juvenna — Kenya (Loita Hills, near Tanzanian border). The Tiger Tooth Aloe. Extremely rare in the wild but one of the most widely cultivated houseplant aloes worldwide — a compact, densely clustering tetraploid with white-spotted leaves and soft marginal teeth. Tender.
Aloe penduliflora — Kenya, Tanzania. Pendant, tubular flowers on a branched inflorescence — the drooping flower orientation is distinctive among East African species. Tender.
Aloe fibrosa — Kenya (coastal hinterland). A grass aloe with narrow, fibrous leaves and slender inflorescences. Rare in cultivation. Tender.
Aloe kedongensis — Kenya (Rift Valley). A shrubby, branching species with narrow leaves, found in dry Rift Valley bushland. Hardy to -2 °C.
Aloe babatiensis — Tanzania (Babati area). A recently described species from rocky outcrops in central Tanzania. Rare in cultivation. Tender.
Aloe leptosiphon — Tanzania (southern highlands). A grass aloe with slender, tubular flowers and narrow leaves. Hardy to -2 °C.
Aloe wilsonii — Kenya, Tanzania. A compact, rosulate species from rocky grasslands. Hardy to -2 °C.
Southern tropical Africa — the Zambezian connection
Aloe excelsa — Zimbabwe, Mozambique, northern South Africa. One of the tallest aloes — trunk to 5 m. Open crown with broad leaves. Red flower racemes. Listed separately under section Pachydendron but ecologically linked to the East African radiation. Hardy to -2 °C.
Aloe spicata — KwaZulu-Natal, Mpumalanga, Eswatini, southern Mozambique, Zimbabwe. A tall-stemmed species (formerly Aloe sessiliflora) with dense, cylindrical, acuminate racemes. Grows on a wide variety of soils from low to high altitudes. Hardy to -2 °C.
Aloe chabaudii — Zimbabwe, Mozambique, Zambia, Malawi. A vigorous, suckering species forming large colonies. Spotted leaves and branched inflorescences of coral-red flowers. An important ornamental in tropical and subtropical gardens. Hardy to -2 °C.
Aloe cameronii — Zimbabwe, Malawi, Mozambique. The Red Aloe. Shrubby, multi-stemmed, suckering. Leaves turn deep coppery red under drought and full sun — one of the most intensely colored foliage aloes in cultivation. Orange-red winter flowers. Tender (–2 °C).
Aloe cryptopoda — Southern tropical Africa (Zimbabwe to Tanzania). A robust, stemless to short-stemmed species with dull green, recurving leaves. Branched inflorescences of orange-red flowers. Hardy to -2 °C.
Aloe christianii — Zimbabwe, Mozambique. A tall-stemmed, single-trunked species from rocky outcrops in the Lowveld. Distinctive, narrow leaves and dense, cylindrical flower racemes. Hardy to -2 °C.
Aloe ortholopha — Zimbabwe (eastern highlands). A distinctive species with upright, keeled leaves arranged in a neat rosette and erect, densely flowered red racemes. The specific epithet means “straight crest,” referring to the upright leaf arrangement. Hardy to -3 °C.
Ethiopia and Eritrea — a likely centre of diversity (~46 species, 67% endemic)
Ethiopia hosts one of the richest concentrations of aloe diversity outside South Africa, with 46 documented species and three subspecies, of which an extraordinary 67.3% are endemic — found nowhere else on Earth. Three local centres of endemism are recognised (Demissew & Nordal 2010), each with characteristic species shaped by the country’s dramatic topography, from Afro-alpine peaks above 3,500 m to scorching lowlands below 500 m. Eritrea, separated from Ethiopia only since 1993, shares several highland species and adds its own coastal endemics along the Red Sea.
The key reference for Ethiopian and Eritrean aloes is Demissew & Nordal (2010), Aloes and Other Lilies of Ethiopia and Eritrea, 2nd edition — the most comprehensive treatment of the group in this region.
North and central highlands — dry montane forest and Afro-alpine
This centre of endemism spans the Ethiopian Plateau from the Simien Mountains to Shewa (North Shewa Zone), at altitudes of 1,500 to 3,700 m.
Aloe camperi — Eritrea, northern Ethiopia. The Popcorn Aloe. Vivid green foliage, puffy salmon-to-yellow flowers in spring. One of the most important medicinal plants in Eritrea, and the first exotic aloe documented as naturalised in South Africa (Table Mountain, Cape Town; Smith et al. 2003 in Bradleya). Hardy to -3 °C.
Aloe elegans — Western Sudan, Eritrea, central Ethiopia. A handsome, large-rosette species with broad, grey-green to blue-green leaves and branched inflorescences of red flowers. Grows in dry montane forest and rocky slopes at 1,500 to 2,500 m. The leaf latex has documented anti-inflammatory properties. Hardy to -2 °C.
Aloe percrassa — Eritrea, northeastern Ethiopia. A robust, short-stemmed species with thick, fleshy, broad leaves — the epithet percrassa means “very thick.” Grows on rocky slopes in dry montane forest. Redefined as a species by Gilbert & Sebsebe (1997). Hardy to -2 °C.
Aloe debrana — Ethiopia (central highlands, North Shewa Zone). A common highland endemic used industrially as a thickening agent in textile printing (jute bag production for Ethiopian export coffee packaging). Grows in dry montane forest at 2,000 to 3,000 m. Recently modelled for climate change vulnerability (Ecological Processes, 2024). Least Concern. Hardy to -3 °C.
Aloe ankoberensis — Ethiopia (Ankober area, North Shewa). An Afro-alpine endemic growing at altitudes up to 3,500 m — one of the highest-altitude aloes anywhere. Extremely restricted range. Classified as Endangered (IUCN). Threatened by habitat shrinkage under all modelled climate change scenarios. Rarely cultivated. Hardy to -5 °C (inferred from altitude).
Aloe sinana — Ethiopia (Bale and Arsi highlands). An endemic highland species from the eastern side of the Rift Valley. Poorly known. Hardy to -3 °C (inferred).
Aloe pulcherrima — Ethiopia (central highlands). The epithet means “most beautiful” — a large-rosette species described by Gilbert & Sebsebe (1997). Endemic. Grows in dry montane forest. Hardy to -2 °C.
Aloe schelpei — Ethiopia (central-western highlands). Named for the South African botanist E.A.C.L.E. Schelpe. An endemic species from rocky mountain slopes. Hardy to -2 °C.
Aloe monticola — Ethiopia (central highlands). A mountain species (monticola = “mountain-dweller”) from rocky slopes and cliff faces. Endemic. Hardy to -3 °C (inferred).
Aloe adigratana — Ethiopia (Tigray region, near Adigrat). A northern highland endemic with documented anti-inflammatory compounds in its leaf latex. Grows on rocky slopes in dry montane vegetation. Hardy to -2 °C.
Aloe clarkei — Ethiopia (central highlands). A recently described endemic species. Poorly known in cultivation. Hardy to -2 °C (inferred).
Aloe yavellana — Ethiopia (southern highlands). A dry montane forest species, classified as Endangered (IUCN). Hardy to -2 °C.
Aloe tewoldei — Ethiopia. A rare cliff-dwelling endemic, classified as Near Threatened (IUCN). Described by Gilbert & Sebsebe (1997). Barely known in cultivation.
Aloe kefaensis — Ethiopia (Kefa/Kaffa region, southwestern highlands). An endemic described by Gilbert & Sebsebe (1997) from the moist montane forests of the coffee homeland. Rarely cultivated.
Aloe benishangulana — Ethiopia (Benishangul-Gumuz region, western lowlands). An endemic from the hot western lowlands approaching the Sudanese border — ecologically distinct from the highland endemics. Tender.
Eastern and southeastern highlands and lowlands
Aloe harlana — Ethiopia (Harar region, eastern highlands). A compact, spotted species from high-altitude grasslands. Classified as Endangered (IUCN). One of the more ornamental Ethiopian endemics. Hardy to -2 °C.
Aloe jacksonii — Ethiopia (Bale region). A distinctive endemic with a compact rosette and bicolored flowers. Described in detail by Walker (2017) alongside Aloe elkerriana. Hardy to -2 °C.
Aloe elkerriana — Ethiopia (Bale region). An endemic from the southeastern highlands, described by Dioli & McCoy. Compact rosettes on rocky slopes. Hardy to -2 °C.
Southern Ethiopia — Acacia-Commiphora woodlands and dry lowlands
The hot, arid lowlands of southern Ethiopia, extending toward the Kenyan and Somali borders, host a distinct suite of aloe species adapted to extreme aridity and the Acacia-Commiphora woodland ecosystem.
Aloe pirottae — southern and eastern Ethiopia, northeastern Kenya. A robust species from dry Acacia-Commiphora woodland. One of the more widely distributed Ethiopian lowland aloes. Tender.
Aloe calidophila — Ethiopia, Kenya (arid lowlands). The epithet means “heat-loving” — a species from hot, dry bushland. Threatened by overharvesting for medicinal use. Tender.
Aloe gilbertii — Ethiopia (southern lowlands). An endemic with documented importance in degraded rangeland rehabilitation: local communities transplant whole plants to stabilize soils and restore vegetation. Multiple uses including soap and lotion production. Tender.
Aloe ellenbeckii — southern Ethiopia, northern Kenya. A small, stemless to short-stemmed species from dry lowlands. Compact rosettes. Tender.
Aloe otallensis — Ethiopia (southern lowlands). An endemic from the Acacia-Commiphora zone. Poorly known. Tender.
Aloe retrospiciens — Ethiopia. An endemic classified as Vulnerable (IUCN). Threatened by habitat degradation. Tender.
Aloe friisii — Ethiopia. An endemic from the southern lowlands. Named for the Danish botanist Ib Friis. Rarely cultivated. Tender.
Aloe mcloughlinii — Ethiopia. A lowland endemic from the Acacia-Commiphora bushland. Tender.
Aloe omoana — Ethiopia (Omo Valley). An endemic from one of the hottest and most remote regions of the country. Tender.
Desert and semi-desert scrubland
Aloe bertemariae — Ethiopia (Afar region and eastern lowlands). An endemic from the scorching desert and semi-desert scrubland of the Afar Triangle — one of the hottest environments occupied by any aloe. Tender.
Aloe citrina — Ethiopia. A desert-scrubland endemic with yellowish flowers (citrina = lemon-coloured). Tender.
Eritrean species
Aloe trichosantha — Eritrea, Ethiopia. A shrubby species with narrow, grey-green leaves and characteristic hairy (trichosantha = “hairy-flowered”) flower buds. Multiple subspecies including subsp. longiflora (Gilbert & Sebsebe 1997). Hardy to -2 °C.
Aloe massawana — Eritrea, Djibouti, Ethiopia. A coastal species from the Red Sea region (sometimes listed as Aloe eumassawana S.Carter, M.G.Gilbert & Sebsebe — a name applied to distinguish it from nomenclatural confusion). Hot, arid, salt-influenced coastal habitats. Tender.
Aloe megalacantha — Ethiopia, Eritrea, Somalia, northern Kenya. A variable, widespread species with large marginal teeth (megalacantha = “large-spined”). Multiple subspecies including subsp. alticola (Gilbert & Sebsebe 1997) from high-altitude forms. Hardy to -2 °C.
Horn of Africa, Arabian Peninsula and Socotra (~90 + ~45 species)
A distinct geographic clade that includes the Arabian Peninsula — the northernmost natural range of the genus. Aloe vera belongs to this clade, confirming its Arabian origin. Somalia alone hosts approximately 45 species, making it the third richest country for aloe diversity after South Africa and Ethiopia.
Arabian Peninsula and Socotra
Aloe vera — Arabian Peninsula (precise wild origin debated; likely Yemen/Oman region). The most commercially important aloe. Cultivated worldwide for its leaf gel. Naturalised across the tropics and the Mediterranean. Hardy to -2 °C. Suckering, grey-green, yellow flowers.
Aloe officinalis — Arabian Peninsula (Yemen, Oman). Closely related to Aloe vera. Rarely cultivated.
Aloe perryi — Socotra. The Socotran aloe. Compact rosettes with beautiful red-spotted leaves. Source of Socotrine aloes, one of the most ancient traded plant products — mentioned by Dioscorides in the first century AD and traded along the Indian Ocean routes for over two millennia. Tender.
Aloe inermis — Yemen. A distinctive stemless species with broad, smooth, unspotted leaves. Yellow flowers. The epithet means “unarmed” — the leaves are entirely toothless, a rarity among aloes. Tender.
Aloe rubroviolacea — Arabian Peninsula (Saudi Arabia, Yemen). A large, solitary species with distinctive reddish-violet leaf colouration — the most intensely pigmented leaves of any aloe. One of the few aloes native to Saudi Arabia. Tender.
Aloe tomentosa — Yemen. A rare species with distinctively hairy leaves — unusual among aloes. Tender.
Aloe niebuhriana — Yemen. A shrubby species named after the Danish explorer Carsten Niebuhr, who documented Arabian flora in the eighteenth century. Tender.
Aloe eremophila — Southern Oman. A rare, solitary species from the arid interior. Tender.
Aloe porphyrostachys — Saudi Arabia (Jabal Radhwa, Hejaz coast). A rare endemic from the Red Sea coastal mountains — one of the northernmost natural occurrences of the genus. Tender.
Somalia (~45 species)
Somalia is the third richest country for aloe diversity, with approximately 45 species — many of them endemic to the Horn of Africa. The Somali flora remains incompletely explored, and new species continue to be described.
Aloe jucunda — Somalia (northern limestone plateaus). A miniature species, barely ten centimetres across. Heavily white-spotted, very ornamental — one of the most beautiful dwarf aloes in the genus. Popular among collectors. Tender.
Aloe somaliensis — Somalia. A variable species from the arid interior, with multiple described varieties. Heavily white-spotted leaves, compact rosettes. An important ornamental in collections. Tender.
Aloe elegantissima — Northern Somalia. The epithet means “most elegant” — a striking species with long, narrow, recurving leaves and distinctive red flowers. Rare in cultivation. Tender.
Aloe whitcombei — Somalia (coastal plains). A small to medium species from the semi-desert lowlands. Tender.
Aloe ruspoliana — Somalia, southeastern Ethiopia. A tall-stemmed species from dry bushland, named after the Italian explorer Prince Ruspoli. Branched inflorescences of red flowers. Tender.
Aloe microdonta — Somalia. A species whose leaf exudate is traditionally dissolved in water and drunk to treat jaundice; the juice is also applied topically for skin diseases. Contains unique compounds microdontin A and B. Tender.
Ethiopia / Somalia / Djibouti — shared and trans-border species
Aloe rivae — Ethiopia, Somalia, Kenya. A robust species from dry lowlands. Red-orange flowers. One of the more widespread Horn of Africa lowland aloes. Tender.
Aloe deserti — Kenya, Ethiopia (arid lowlands). Short-stemmed, grey-green. Well-adapted to extreme aridity — survives in some of the driest habitats occupied by any aloe. Tender.
Aloe pubescens — Ethiopia. An endemic classified as Near Threatened (IUCN). The epithet refers to fine hairs on the leaf surface. Rare in cultivation. Tender.
Aloe rugosifolia — Ethiopia. An endemic classified as Vulnerable (IUCN). The epithet means “wrinkle-leaved.” Compact rosettes. Rare in cultivation. Tender.
Aloe ghibensis — Ethiopia (Ogaden region). An endemic from the Somali-Ethiopian border region. Poorly known. Tender.
Aloe downsiana — Ethiopia. An endemic. Rarely cultivated. Tender.
Aloe harlana — Ethiopia (Harar region). Listed above under Eastern highlands. Endangered (IUCN).
Conservation note. The aloe flora of Ethiopia and the Horn of Africa faces multiple threats: habitat destruction from urban and agricultural expansion, overharvesting for medicinal and cosmetic use, and climate change — modelling studies predict significant habitat shrinkage for highland endemics like Aloe ankoberensis and Aloe debrana under all future climate scenarios. Out of Ethiopia’s 46 aloe species, six are on the IUCN Red List: Aloe harlana and Aloe yavellana (Endangered), Aloe tewoldei and Aloe pubescens (Near Threatened), Aloe retrospiciens and Aloe rugosifolia (Vulnerable). Many remaining species are still data-deficient — the true conservation picture may be worse than current assessments suggest.
Madagascar and the western Indian Ocean islands (~120 species)
Malagasy aloes form a fully supported monophyletic clade — they represent a single colonisation event from mainland Africa, followed by extensive diversification on the island. Many species produce fleshy berries rather than dry capsules (formerly separated as the genus Lomatophyllum). Madagascar is the second largest centre of aloe diversity after South Africa, with approximately 120 species — virtually all endemic.
Aloe vaombe — southern Madagascar. A tall, single-stemmed species with dark red leaves and spectacular red flower spikes. One of the most dramatic Malagasy aloes. Tender.
Aloe capitata — central and southern Madagascar. Variable, with dense capitate inflorescences. Several varieties. An important ornamental in tropical gardens. Tender.
Aloe descoingsii — southern Madagascar. One of the smallest aloes — rosettes barely three centimetres across. A miniature for collectors. Named after the French botanist Bernard Descoings. Tender.
Aloe bakeri — central Madagascar. A grass-like aloe with narrow, spotted leaves. Popular in collections. Tender.
Aloe bulbillifera — Madagascar. Produces bulbils on the inflorescence, like some agaves — a rare trait among aloes. Tender.
Aloe suzannae — southern Madagascar. A massive tree aloe (now placed in Aloidendron by some authors). Trunk to 3–4 m. Critically endangered — among the rarest aloes on Earth. Tender.
Aloe helenae — southeastern Madagascar. A single-stemmed species with broad, recurved leaves. Critically endangered. Tender.
Aloe rauhii — central Madagascar. A compact, dwarf species with heavily white-spotted leaves. Very ornamental, popular among collectors. Several cultivars, including the striking ‘Snow Flake.’ Tender.
Aloe parvula — central Madagascar. A tiny species, rosettes to five centimetres. Blue-green leaves with white spots. Tender. Collector’s miniature.
Aloe isaloensis — southwestern Madagascar (Isalo massif). A short-stemmed species from sandstone outcrops. Red flowers. Tender.
Aloe divaricata — southern Madagascar. A branched, shrubby species from spiny thicket. Yellow flowers. Tender.
Aloe acutissima — central Madagascar. Narrow, sharply pointed leaves. Orange flowers. Tender.
Aloe deltoideodonta — central and northern Madagascar. Variable, suckering, with distinctive deltoid marginal teeth. Multiple varieties. Tender.
Aloe macroclada — Madagascar, Comoros Islands. A large, robust species with broad leaves and branched inflorescences. One of the most widely distributed Malagasy aloes. Tender.
Segregated genera: species formerly placed in Aloe
Aloidendron — the tree aloes (6–7 species)
Phylogenomically divided into a southwestern African desert clade (short, ventricose flowers, bird-pollinated) and an eastern African / Malagasy clade (longer, curved flowers, sunbird-pollinated).
Aloidendron dichotomum (syn. Aloe dichotoma) — Namibia, Northern Cape. The quiver tree. Forked, corky trunk to 7–9 m. Iconic of the Namaqualand landscape. Named for the San people’s practice of hollowing branches for arrow quivers. Hardy to -5 °C in dry soil.
Aloidendron pillansii (syn. Aloe pillansii) — Northern Cape, southern Namibia. The bastard quiver tree or giant quiver tree. One of the rarest aloes — trunk to 10 m. CITES Appendix I. Critically endangered in the wild. Hardy to -3 °C.
Aloidendron ramosissimum (syn. Aloe ramosissima) — Northern Cape (Richtersveld). The maiden’s quiver tree. Much-branched, densely forked, to 3 m. Hardy to -3 °C. Spectacular in succulent gardens.
Aloidendron barberae (syn. Aloe barberae, Aloe bainesii) — Eastern Cape, KwaZulu-Natal. The largest of all aloes — trunk to 15–18 m with a massive crown. Spectacular in warm gardens. Hardy to -3 °C. Fast-growing for a tree aloe.
Aloidendron tongaense (syn. Aloe tongaensis) — northern KwaZulu-Natal, Mozambique. Humid coastal forest. Tall trunk, broad rosette. Tender.
Aloidendron eminens (syn. Aloe eminens) — Somalia. Rare, endemic to arid thicket. Trunk to 5–9 m. Long, curved, pendant flowers pollinated by sunbirds. Tender.
Aloestrela (1 specie)
Aloestrela suzannae (syn. Aloe suzannae) — southern Madagascar. Placed in Aloidendron by some authorities following phylogenomic studies (sister to A. eminens ?). Massive trunk to 3–4 m. Critically endangered. Tender.
Aloiampelos — the scrambling aloes (~7 species)
Shrubby plants with thin, slender stems that scramble through or over neighbouring vegetation. Phylogenetically basal — among the earliest-diverging lineages in the alooid group.
Aloiampelos ciliaris (syn. Aloe ciliaris) — Eastern Cape. The fastest-growing aloe relative — can extend several metres in a single season. Scrambling stems, bright red tubular flowers. Excellent wall and fence cover. Hardy to -5 °C.
Aloiampelos striatula (syn. Aloe striatula) — Eastern Cape (high altitude). The hardiest aloe relative — to -10 °C or below in dry soil. Scrambling shrub with bright green, striated leaves. Yellow flowers. The only “aloe” for USDA zone 7. A key species for cold-climate exotic gardens.
Aloiampelos tenuior (syn. Aloe tenuior) — Eastern Cape. The most slender-stemmed scrambling aloe. Thin, whip-like stems. Yellow flowers. Hardy to -3 °C.
Aloiampelos gracilis (syn. Aloe gracilis) — Eastern Cape. Similar to A. ciliaris but more compact. Orange-red flowers. Hardy to -4 °C.
Aloiampelos commixta (syn. Aloe commixta) — Western Cape (Table Mountain). A rare, cliff-dwelling scrambler from the Cape Peninsula. Hardy to -3 °C.
Aloiampelos juddii (syn. Aloe juddii) — Western Cape. An extremely rare, recently described species. Hardy to -3 °C.
Aristaloe — monotypic
Aristaloe aristata (syn. Aloe aristata) — widespread across South Africa (Eastern Cape, Free State, Lesotho). The lace aloe, guinea-fowl aloe or torch plant. Dense, compact rosette with white tuberculate markings and soft, bristle-like leaf tips. Looks more like a Haworthia than an Aloe — molecular studies confirm it is more closely related to the haworthioid group. Hardy to -10 °C. One of the best “aloes” for cold climates and containers. Produces orange tubular flowers prolifically.
Kumara — the fan aloes (2 species)
Endemic to the Western Cape fynbos of South Africa. Unique among all alooids for their distichous (fan-shaped) leaf arrangement — no other genus in the group produces leaves in two ranks.
Kumara plicatilis (syn. Aloe plicatilis) — Western Cape (fynbos). The fan aloe. Forked trunk with grey-green fans of strap-shaped, succulent leaves. Can reach 3–5 m with age. Red tubular flowers in spring. Hardy to -3 °C. Slow-growing but unmistakable — a mature specimen is one of the most photogenic succulents on Earth. Prefers winter-rainfall conditions.
Kumara haemanthifolia (syn. Aloe haemanthifolia) — Western Cape (high-altitude fynbos, mountains above Franschhoek). Rare, compact, with distinctive soft, broad leaves unlike any other alooid. Hardy to -3 °C. A botanical curiosity — almost never seen in cultivation.
Gonialoe — section Serrulatae segregates (4 species)
Small, compact aloes with distinctively banded or variegated leaves. Phylogenetically closer to the haworthioid group (Haworthia, Gasteria, Astroloba) than to true aloes.
Gonialoe variegata (syn. Aloe variegata) — Northern Cape, Free State, Western Cape. The tiger aloe or partridge-breasted aloe. Compact rosette with beautifully banded green and white leaves arranged in three ranks. Tolerates low light — one of the best aloes for indoor culture. Hardy to -5 °C. One of the most popular succulent houseplants worldwide.
Gonialoe sladeniana (syn. Aloe sladeniana) — Botswana, Namibia. Compact, strongly banded, similar to G. variegata but with narrower leaves. Rare in cultivation.
Gonialoe dinteri (syn. Aloe dinteri) — Namibia. A small, compact species with white-banded leaves. Hardy to -3 °C. Uncommon in cultivation.
Conservation
Many aloe species are threatened in the wild — by habitat loss, overgrazing, urban development, illegal collection and, increasingly, by the spread of the cycad aulacaspis scale (Aulacaspis yasumatsui), which also attacks some aloes in cultivation. All species in the genus Aloe (and its segregate genera) are listed under CITES Appendix II, meaning international trade is regulated and requires permits. Aloe albida, Aloe pillansii (now Aloidendron pillansii), Aloe polyphylla and Aloe vossii are listed under CITES Appendix I — the highest level of protection, prohibiting all commercial trade.
For gardeners, this means: always buy from reputable nurseries that sell legally propagated plants. Never purchase wild-collected aloes. Seed-raised and offset-propagated plants are both legal and — because they are adapted to cultivation — far more likely to thrive in your garden than a stressed, wild-collected specimen.
Web resources
Plants of the World Online (POWO) — Kew Royal Botanic Gardens. The authoritative global database for accepted plant names. The reference we use on this site for nomenclature. Search any aloe species to verify its accepted name, synonymy, distribution and taxonomic status. Essential for resolving the constant name changes in the alooid group. powo.science.kew.org
PlantZAfrica — South African National Biodiversity Institute (SANBI). The finest single online resource on southern African aloes. Detailed species accounts written by specialists from the Pretoria National Botanical Garden and the Compton Herbarium, with high-quality photographs, distribution maps and cultivation notes. The genus page on aloes is an excellent starting point. pza.sanbi.org
World Checklist of Selected Plant Families (WCSP) — Kew. A comprehensive checklist of all accepted species in Asphodelaceae (including all alooid genera). More technical than POWO but invaluable for checking infraspecific taxa, basionyms and publication references. wcsp.science.kew.org
IUCN Red List of Threatened Species. Conservation assessments for aloe species. Search by species name to find the current threat category, population trends, habitat data and references. Many aloes have not yet been assessed — a reflection of the scale of the genus rather than a lack of concern. iucnredlist.org
CITES Species+ database. Searchable database for CITES-listed species. Verify the trade status of any aloe before buying, selling or transporting across borders. speciesplus.net
Encyclopaedia of Succulents — Llifle. A community-driven encyclopaedia with cultivation notes, photographs and synonymy for hundreds of aloe species. The quality of entries varies, but the best are detailed and well-illustrated. llifle.com
Aloes of the World project — Kew. An ongoing research initiative at the Royal Botanic Gardens, Kew, aimed at reconstructing a complete phylogeny of the aloes using nuclear DNA sequencing. The project has produced the most comprehensive molecular phylogeny of the genus to date (Woudstra et al. 2025). Follow the project for updates on classification changes. kew.org
iNaturalist. A citizen-science platform where aloe observations from around the world are uploaded with photographs and GPS coordinates. Particularly valuable for seeing species in habitat and understanding natural variation. Search “Aloe” and filter by region. inaturalist.org
Succulents and More (blog by Gerhard Bock). A Californian garden blog with outstanding coverage of aloe cultivation in Mediterranean climates, nursery visits and cultivar reviews. The 2014 post on the reclassification of Aloe into six genera remains one of the clearest lay explanations available. succulentsandmore.com
The Belmont Rooster. A comprehensive photographic database of aloe species and hybrids, with current nomenclature and cultivation notes. Particularly strong on hybrid identification and naming. thebelmontrooster.com
Bibliography
Monographs and floras
Berger A. (1908). Liliaceae–Asphodeloideae–Aloineae. In: Engler A. (ed.), Das Pflanzenreich, IV.38.III.II. Engelmann, Leipzig. — The first comprehensive infrageneric classification of Aloe. Many of Berger’s sections are still used today and have been confirmed as monophyletic by molecular studies.
Reynolds G.W. (1950). The Aloes of South Africa. Trustees of The Aloes of South Africa Book Fund, Johannesburg. — The definitive monograph on southern African aloes. Over 500 pages of descriptions, illustrations and distribution maps. Out of print but available in specialist libraries and occasionally from antiquarian dealers.
Reynolds G.W. (1966). The Aloes of Tropical Africa and Madagascar. Trustees of The Aloes Book Fund, Mbabane, Swaziland. — The companion volume to the 1950 work, covering tropical and Malagasy species. Essential reference for East African and Malagasy aloes.
Glen H.F., Hardy D.S. (2000). Aloaceae (First part): Aloe. Flora of Southern Africa, vol. 5, part 1, fascicle 1. National Botanical Institute, Pretoria. — The most recent formal treatment of South African aloes in a flora context. Updates and refines Reynolds (1950).
Carter S., Lavranos J.J., Newton L.E., Walker C.C. (2011). Aloes: The Definitive Guide. Kew Publishing, Royal Botanic Gardens, Kew. — The most comprehensive modern reference on all aloe species worldwide. Over 700 pages with photographs, distribution maps and concise species accounts. The standard desktop reference for aloe enthusiasts.
Van Wyk B.-E., Smith G. (2014). Guide to the Aloes of South Africa. Third edition. Briza Publications, Pretoria. — An accessible field guide to all South African aloe species, with excellent photographs and concise descriptions. Ideal for identification.
Molecular phylogenetics and classification
Grace O.M., Klopper R.R., Figueiredo E., Smith G.F. (2013). The aloe names book. Strelitzia 29. South African National Biodiversity Institute, Pretoria, and Royal Botanic Gardens, Kew. — A nomenclatural reference for all names published in the alooid group.
Manning J.C., Boatwright J.S., Daru B.H., Maurin O., Van der Bank M. (2014). A molecular phylogeny and generic classification of Asphodelaceae subfamily Alooideae: a final resolution of the prickly issue of polyphyly in the alooids? Systematic Botany, 39(1): 55–74. — The landmark paper that split Aloe into six genera (Aloe, Aloidendron, Aloiampelos, Aristaloe, Kumara, Gonialoe) and redefined the alooid genera.
Grace O.M., Buerki S., Symonds M.R.E., Forest F., van Wyk A.E., Smith G.F., Klopper R.R., Bjorå C.S., Neale S., Demissew S., Hardy C.R., Rønsted N. (2015). Evolutionary history and leaf succulence as explanations for medicinal use in aloes and the global popularity of Aloe vera. BMC Evolutionary Biology, 15: 29. — A key phylogenetic study that revealed the geographic structure of aloe clades and clarified the Arabian origin of Aloe vera.
Woudstra Y., Grace O.M., Klopper R.R., Buerki S. et al. (2025). Nuclear phylogenomics reveals strong geographic patterns in the evolutionary history of Aloe and related genera (alooids). Annals of Botany. — The most recent and comprehensive molecular phylogeny of the alooids, using nuclear genome target capture sequencing on over 400 species. Confirms the monophyly of segregated genera and reveals that geography is a better classifier than morphology for tropical African aloes.
Woudstra Y., Klopper R.R. et al. (2021). Museomics clarifies the classification of Aloidendron (Asphodelaceae), the iconic African tree aloes. Frontiers in Plant Science, 10: 1227. — Resolved phylogenetic relationships among tree aloes using herbarium genomics.
Conservation and trade
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Appendices I, II and III. cites.org — The regulatory framework governing international trade in all Aloe species.
Newton L.E. (2001). Aloe. In: Eggli U. (ed.), Illustrated Handbook of Succulent Plants: Monocotyledons. Springer, Berlin. — Species accounts with conservation notes.
Cultivation
Jeppe B. (1969). South African Aloes. Purnell, Cape Town. — A classic, still useful cultivation guide focused on South African species.
Ritter M., Underbill L.G. (2022). Flowering phenology of southern African aloes. South African Journal of Botany, 144: 251–262. — Data on flowering seasons across species — valuable for planning garden colour.
Going further
The genus Aloe — even in its modern, narrower circumscription — is one of the most rewarding groups of plants a gardener can explore. They are beautiful, floriferous, low-maintenance, available in an extraordinary range of sizes and forms, and they flower faithfully year after year. Our site offers detailed species profiles for every commonly cultivated aloe, along with guides on care, frost hardiness, propagation and pest management. Browse the species list below, or start with one of our thematic guides to find the aloe that is right for your garden, your climate and your ambitions.