In 1975, Encephalartos pterogonus was declared extinct in its habitat. The small population on Mount Mruwere (Monte Urueri) — a massive granite inselberg in the Manica province of central Mozambique — had been plundered by wealthy collectors, and no plants could be found on the mountain. The species appeared to be lost.
Then something unusual happened. Someone planted cycads back.
Approximately 1000 seedlings were reintroduced to the mountain. Not all survived — the transition from nursery to granite outcrop is brutal for any plant, let alone a cycad seedling — but enough did. Recent reports indicate that 246 mature plants, 112 smaller plants, and 300–400 seedlings now grow on Mount Mruwere, descendants or survivors of that reintroduction effort. Another population on a nearby inselberg may also belong to the species. Encephalartos pterogonus is not out of danger — it is still classified as Critically Endangered by the IUCN — but it is, uniquely among the most threatened members of the genus Encephalartos, a species that has been brought back from the dead.
This makes pterogonus an extraordinary case study in cycad conservation. It demonstrates that reintroduction can work — that a species stripped from its habitat by collectors can be returned, can establish, can recruit seedlings, can begin to rebuild a self-sustaining population. It also demonstrates the limits: the reintroduced population remains small, remains confined to one mountain, and remains vulnerable to the same collectors who eliminated the original population. The story of pterogonus is not yet a success story. It is a story in progress — and the ending has not been written.
Taxonomy and nomenclature
Encephalartos pterogonus R.A. Dyer & I. Verd. was first published in 1969 in Kirkia (volume 7: 147–158, page 151), in the landmark paper “Encephalartos manikensis and its near allies” that segregated the manikensis complex. The holotype (R.C. Munch 451) was collected from Mount Mruwere, north of Vila Pery (now Chimoio), Mozambique, in October 1949 — twenty years before the formal description. The holotype is deposited at PRE (Pretoria), with an isotype at SRGH (Harare).
The epithet pterogonus combines the Greek pteron (“wing”) and gonas (“seed” or “angle”), referring to the acute, sometimes wing-like and toothed lateral angles of the bulla (the swollen terminal portion of the cone scale), particularly of the microsporophylls (pollen-bearing scales). Haynes (2022) confirms this etymology. The winged cone scales are the single most important diagnostic character of the species — the morphological feature that justifies its separation from manikensis sensu stricto.
Raymond C. Munch (1901–1985) — the Rusape farmer and cycad collector who also provided the type material for E. munchii (Munch 452, Zembe Mountain) — collected the pterogonus holotype on a separate expedition to Mount Mruwere. The two collections, numbered consecutively (451 and 452), were made on different mountains during what was presumably a single extended field trip through the granite inselbergs of the Manica province. Dyer and Verdoorn described both species in the same 1969 paper.
Within the manikensis complex, pterogonus is distinguished by its unique winged microsporophylls: the lower edges of the pollen cone scales bear projections or lobes that extend beyond the terminal facets — a character found in no other member of the complex. The key within the complex runs as follows: manikensis has thick, flat, uncurved, unwinged scales; chimanimaniensis has curving scales; concinnus has smaller cones overall; munchii has bluish-green cones and leaves; and pterogonus has winged scales. POWO gives the native range as “Mozambique (Manica).” No synonyms exist.
Common names: Winged-scale cycad, toothed-cone cycad (informal English).
Morphological description
Habit and caudex: Encephalartos pterogonus is a medium-sized, robust cycad. The trunk is erect, reaching up to 1.5 m in height (rarely 2.1 m according to LLIFLE) and approximately 40 cm in diameter. The species produces suckers from the base, forming clumps — a “tends to sucker well” character (Africa Cycads) that provides both ornamental value and propagation material.
Leaves: The fronds are 100–150 cm long (LLIFLE gives 1–1.5 m; Wikipedia gives 1.2–1.5 m), shiny mid-green, and — critically — flat in cross-section, with opposing leaflets inserted at approximately 180° on the rachis. This flat leaf profile is shared with E. aplanatus but not with the keeled leaves of the South African blue species. The rachis is green, straight, stiff, and not spirally twisted — contrasting with the corkscrew rachis of dolomiticus.
The median leaflets are lanceolate, 15–18 cm long and 20–25 mm wide (substantially wider than those of dolomiticus at 10–14 mm), weakly discolorous (slightly different colour on upper and lower surfaces), and arranged at an obtuse angle (45–80°) on the rachis. Basal leaflets reduce to spines. LLIFLE notes a distinguishing leaflet character: 1–3 prominent spines on the upper margin of most leaflets close to the base, with the lower margin also bearing 1–3 teeth. This spine pattern — concentrated at the base of the leaflet’s upper margin — is more specific than the generalised marginal armament of manikensis and provides a useful identification feature.
The foliage closely resembles that of Encephalartos manikensis. LLIFLE states this explicitly: the leaves “closely resemble the foliage of Encephalartos manikensis.” Vegetative identification of pterogonus without cones is difficult; positive identification requires either cone material (to examine the winged scales) or knowledge of the plant’s provenance (Mount Mruwere or adjacent mountains).
Reproductive structures — the diagnostic wings: Male cones are 2–3 per plant, narrowly ovoid, green, 30–38 cm long and 9–11 cm in diameter. Female cones are 2–3, ovoid, green, 30–40 cm long and 16–18 cm in diameter. Both sexes’ cones superficially resemble those of the Zimbabwean form of manikensis. Seeds are oblong, 30–35 mm long and 20–23 mm wide, with a red or orange sarcotesta.
The diagnostic character is on the male cone scales: the microsporophylls bear wing-like projections or lobes on their lower lateral edges that extend beyond the terminal facets. These wings are visible on examination of an intact male cone — the lower edge of each scale projects outward in a thin, sometimes toothed flange that gives the cone a subtly different texture from the smooth-scaled cones of manikensis. The character is not dramatic to the casual observer but is consistent and diagnostic: no other Encephalartos species produces winged microsporophylls.
Distribution and natural habitat
Encephalartos pterogonus is endemic to Mount Mruwere (Monte Urueri) and possibly adjacent mountains in the Manica province of Mozambique, north of Chimoio (formerly Vila Pery). POWO gives the native range as “Mozambique (Manica).” LLIFLE provides precise range data: extent of occurrence 35 km², area of occupancy less than 10 km². Africa Cycads notes: “Another population on a nearby inselberg may also belong to E. pterogonus” — a tantalising possibility that, if confirmed, would double the species’ known distribution.
The altitude range is 700–1000 m. The habitat consists of granite outcrops, with plants found in or near forested areas on the mountain slopes. Mount Mruwere is a large granite inselberg — one of the chain of granite and gneiss outcrops running along the Zimbabwe–Mozambique border that also includes Zembe Mountain (home of E. munchii) and the mountains near Gravelotte (home of E. dyerianus). Each inselberg supports its own cycad population, and the taxonomic question of whether these populations represent truly distinct species or ecotypes of a single variable ancestor remains open.
Conservation — death, resurrection, and fragile survival
The conservation history of Encephalartos pterogonus is unique in the genus. It is a three-act story:
Act I — Discovery and destruction (1949–1975). The species was discovered in 1949 by R.C. Munch, who collected the holotype from Mount Mruwere. The population “was never large” (LLIFLE, Africa Cycads). Between 1949 and 1975, the mountain was stripped by collectors. LLIFLE states: “Most of the plants have been plundered by wealthy collectors and the species was declared extinct in its habitat by 1975.” The speed of destruction is remarkable: a species discovered, described, and eliminated from the wild within a single human generation.
Act II — Reintroduction (~1975–present). At some point after the population’s collapse, a reintroduction effort was undertaken. Approximately 1000 seedlings were planted on Mount Mruwere. The details of this effort — who organised it, when exactly it occurred, how the seedlings were produced, whether they came from seed collected on Mruwere before the collapse or from cultivated plants elsewhere — are poorly documented in the available literature. But the results are documented: LLIFLE and Africa Cycads report that “at least 246 mature plants, 112 smaller plants and 300–400 seedlings” have survived from that initial reintroduction of 1000.
The survival rate — roughly 60–80% if we count all size classes — is remarkably good for a cycad reintroduction on a granite mountain. Cycad seedlings are vulnerable to drought, fire, herbivory, and root rot; that the majority survived suggests either favourable conditions on Mruwere or careful post-planting management, or both.
Act III — Ongoing vulnerability (present). The reintroduced population is still small (fewer than 700 individuals across all size classes), still confined to one mountain (possibly two), and still vulnerable to the same collector pressure that eliminated the original population. The IUCN classifies the species as Critically Endangered (CR) under criteria B1ab(iii,v)+2ab(iii,v). The EOO of 35 km² and AOO of less than 10 km² place it firmly in the B criteria danger zone.
The reintroduction of pterogonus is, as far as the available literature indicates, the only documented successful reintroduction of an Encephalartos species to its original habitat. This makes it a proof of concept — evidence that reintroduction is not merely a theoretical possibility but a practical reality. The question for nubimontanus, chimanimaniensis, and the other EW or near-EW species is whether the pterogonus model can be replicated: can seedlings be produced in sufficient quantity, planted on the original sites, and protected long enough to establish self-sustaining populations?
The winged scale — anatomy of a diagnostic character
The wing-like projections on the pollen cone scales of pterogonus are the species’ taxonomic raison d’être — the single morphological character that justifies its separation from manikensis sensu stricto. But what are these wings, and why does pterogonus have them when no other Encephalartos does?
The “wing” is a thin, lateral extension of the bulla — the swollen terminal facet of each microsporophyll. In most Encephalartos species, the bulla is roughly hexagonal or rhombic in face view, with smooth or slightly rounded lateral edges. In pterogonus, the lateral edges are produced into acute angles or lobes that project beyond the main body of the scale, sometimes bearing small teeth. The effect, when the cone is intact, is of a slightly rough or irregular cone surface — each scale’s wings overlapping or abutting the wings of adjacent scales, creating a texture that is subtly but consistently different from the smooth cones of manikensis.
The function of the wings is unknown. Hypotheses include: (1) increased surface area for pollen presentation to beetle pollinators; (2) a mechanical function, perhaps helping to retain or channel pollen within the cone structure; (3) a neutral morphological variant fixed by genetic drift in a small, isolated population. Without detailed pollination studies — which have never been conducted for pterogonus — the question remains open. The character is, however, consistent: every known male cone from Mount Mruwere shows the winged scales, and no manikensis cone from elsewhere in the range shows them.
Cold hardiness
The 700–1000 m altitude in subtropical Mozambique means mild winters with minimal frost. The species is frost-sensitive.
Practical cold hardiness estimate: USDA Zone 10a–10b (−1 to +4 °C). LLIFLE describes the species as “frost sensitive (USDA zones 10–12)” but notes it “exhibits an unusual amount of cold tolerance by surviving in warm temperate areas as well, only suffering defoliation or leaf burn during extreme winters.” Africa Cycads confirms: “It dislikes frost.” The species is fundamentally subtropical.
Caveat: Young plants with subterranean or barely emergent caudices benefit from soil thermal inertia and may tolerate brief cold events that would damage a mature plant with a 1.5 m exposed trunk. A single isolated success in a warm-temperate garden does not prove the species can survive reliably in frost-prone climates. Keep dry during cool months — wet cold is more damaging than dry cold.
Cultivation — vigorous grower, reluctant coner
Difficulty: 2/5 for vegetative growth; 4/5 for reproduction. LLIFLE: “This cycad is a vigorous grower.” Africa Cycads: “The seedlings grow rapidly, developing into an attractive garden plant with 1 m long leaves in four to five years.” But there is a significant caveat: “It is very difficult to get to cone” (LLIFLE, Africa Cycads). This coning reluctance is a serious conservation problem — if cultivated plants do not cone, they cannot produce seed, and the genetic lineage they represent cannot be propagated sexually.
The contrast with E. cerinus — which “cones frequently and responds well to artificial pollination” — is stark. Encephalartos pterogonus grows vigorously, suckers freely, transplants easily, and produces attractive foliage. But it resists the one thing that matters most for conservation: reproduction.
Light: Full sun to partial shade. The granite-outcrop habitat was open and fully exposed.
Soil: Deep, well-drained sandy loam. Africa Cycads: “It grows in all sorts of soil type, but prefers well-drained, gritty soil with plenty of water, especially in dry weather.” The granite-derived soils of Mount Mruwere are acidic, sandy, and fast-draining.
Watering: Regular and generous during the growing season. Despite the rocky-hillside origin, the species “responds to regular watering and fertilization” (LLIFLE) — more water means faster growth. Reduce in winter.
Growth rate: Fast. Seedlings reach attractive garden size (1 m leaves) within 4–5 years. However, seedlings “can be a little slow to get started for the first couple of years if they are grown in containers which do not allow room for the tap root to develop” (Africa Cycads). Use deep containers from the start.
Transplanting: Easy — a contrast with the transplant-resistant munchii. Africa Cycads recommends removing all leaves before transplanting: “This makes for easier handling and the plant will recover sooner due to less moisture loss.”
Suckering: Abundant. The species “tends to sucker well” (Africa Cycads, LLIFLE), forming multi-stemmed clumps that are both ornamental and a source of vegetative propagation material.
Container culture: Good when young. The moderate trunk size (to 1.5 m) and vigorous growth make pterogonus a satisfying container specimen. Use deep pots to accommodate the tap root. Plants will usually hold two or three crowns of leaves simultaneously.
Propagation: Seed (if obtainable — the coning difficulty makes seed scarce) or suckers. Suckers can be separated from established clumps. Seeds germinate easily but need shade for successful establishment.
Comparison within the manikensis complex
| Character | E. pterogonus | E. munchii | E. chimanimaniensis |
|---|---|---|---|
| Distribution | Mt Mruwere, Manica, Mozambique | Zembe Mt, Manica, Mozambique | Chimanimani Mts, Zimbabwe (extinct?) |
| Cone scale character | Winged projections (unique) | Standard; bluish-green colour | Curving lateral edges |
| Leaf colour | Mid-green, shiny | Soapy green; young flush ice-blue | Bright green, glossy |
| Male cone size | 30–38 × 9–11 cm | 40–65 × 7–9 cm | 50–70 × 8–10 cm (longest) |
| Trunk | To 1.5 m (rarely 2.1 m) × 40 cm | To 1 m × 35 cm (smallest) | To 1.8 m × 45 cm |
| Leaf cross-section | Flat (180° insertion) | Very slight V | Moderately keeled (45–80°) |
| Suckering | Abundant | Present | Occasional |
| Transplant tolerance | Easy | Virtually impossible (mature) | Unknown |
| Coning in cultivation | Very difficult | Not documented | Unknown (too rare) |
| Reintroduction | Yes — 1000 seedlings; 246+ adults survived | No | No (possibly extinct) |
| IUCN status | CR | CR | CR (possibly extinct) |
Mount Mruwere — the mountain that got its cycads back
Mount Mruwere (Monte Urueri) is a granite inselberg — one of the chain of ancient granite outcrops that runs through the Manica province of Mozambique, each a geological island rising from the surrounding lowlands. These inselbergs are biogeographic islands too: their rocky slopes, shallow soils, and exposed summits create microhabitats that differ radically from the surrounding bushveld, supporting plant communities — including cycads — that cannot survive on the lowland substrate. Each inselberg is, in effect, an experiment in isolation: a population of organisms cut off from its nearest relatives by kilometres of unsuitable habitat, free to diverge morphologically and genetically over thousands of generations.
The manikensis complex is the product of this island biogeography. Mount Mruwere produced pterogonus (winged scales). Zembe Mountain produced munchii (blue flush). The Chimanimani Mountains produced chimanimaniensis (curving scales). The broader highlands produced manikensis sensu stricto (the generalist) and concinnus (the small-coned form). Whether these represent genuinely distinct species or ecotypes of a single polymorphic ancestor — whether the winged scale is a species-defining character or an inselberg-specific variant — remains debated. But the practical consequence is clear: each inselberg’s cycad population is an irreplaceable genetic lineage, and losing one population is losing something that cannot be recovered from any other mountain.
Mount Mruwere lost its cycads in 1975. It got them back through reintroduction. The 246 mature plants now growing on the granite slopes are, in a sense, repatriated refugees — descended from seed collected before the collapse (or produced in cultivation from plants taken from the mountain), raised in nurseries, and returned to the rock from which their ancestors grew. Whether these plants carry the full genetic diversity of the original population, or only a subset of it, is unknown. Whether they will attract pollinators, produce viable seed, and recruit the next generation naturally — without human intervention — is the open question that will determine whether the reintroduction is a rescue or merely a delay.
For now, Mount Mruwere stands as the one mountain in the manikensis complex’s range that has cycads on it because humans put them there. The Chimanimani Mountains are empty. Zembe Mountain’s munchii population is a tiny relic. The broader manikensis populations in Zimbabwe and Mozambique persist but face ongoing poaching pressure. Pterogonus, the species that was declared dead in 1975, is the only member of the complex whose population trajectory is currently upward rather than downward. It is a fragile, provisional, deeply uncertain upward — but it is upward. And in the world of Encephalartos conservation, where almost every arrow points toward zero, any upward movement is worth noting.
Authority websites
POWO — Plants of the World Online: https://powo.science.kew.org/…
IUCN Red List: https://www.iucnredlist.org/species/41897/10574244
World List of Cycads: https://cycadlist.org
Bibliography
Dyer, R.A. & Verdoorn, I.C. (1969). Encephalartos manikensis and its near allies. Kirkia 7(1): 147–158, p. 151. [Original description; JSTOR stable/23501059]
Whitelock, L.M. (2002). The Cycads. Timber Press, Portland. 374 pp.
Donaldson, J.S. (ed.) (2003). Cycads: Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group, IUCN, Gland.
Donaldson, J.S. (2010). Encephalartos pterogonus. The IUCN Red List of Threatened Species.
Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31.