Cycas pectinata: description, true range and look-alikes

Cycas pectinata is a tall, tree-like cycad of the foothills of the eastern Himalaya and north-east India, with a smooth grey trunk and very large male cones. Named in 1826, it was only the fourth species of the genus Cycas to be described. For a long time it was thought to range from India to Vietnam and southern China, but a revision published in 2020 split off the eastern populations as Cycas divyadarshanii: according to The World List of Cycads, Cycas pectinata now occurs only in Nepal, Bhutan, Bangladesh and north-east India (Assam, Bihar, Meghalaya, Sikkim and West Bengal). Not every source has adopted this split, and many plants sold under the name come from South-East Asia. The name Cycas jenkinsiana, published in 1854, refers to the same species. It is listed as Vulnerable by the IUCN.

Key facts about Cycas pectinata

Accepted name: Cycas pectinata Buch.-Ham. (1826), accepted by The World List of Cycads (version 2026.08.15); the World Checklist of Vascular Plants (WCVP), on which POWO is based, also accepts it (consulted through GBIF on 31 October 2026)
Former names and synonyms: Cycas jenkinsiana Griff. (1854); Cycas circinalis var. pectinata (Buch.-Ham.) J.Schust. (1932); since 2020 The World List of Cycads places the populations of South-East Asia, Yunnan and Manipur under Cycas divyadarshanii
Family: Cycadaceae, order Cycadales; section Indosinenses
Common names: no established English name; “pectinate sago palm” in a Mississippi State University extension publication; local names in Assamese, Khasi, Nepali, Chinese and Thai (see Common names)
Natural range: Bangladesh, Bhutan, India (Assam, Bihar, Meghalaya, Sikkim, West Bengal), Nepal (The World List of Cycads); a much wider range in sources published before 2020
IUCN status: Vulnerable (VU A2cd+4cd according to The World List of Cycads); current assessment by J. D. Bösenberg published in 2023, an earlier one by Nguyen in 2010
CITES and other protection: CITES Appendix II (family listing, seeds exempt under annotation #4); Annex B in the European Union
Documented hardiness: no reliable measurement for the species in the strict sense; a US extension publication gives it as “reportedly hardy to 26 °F” (−3 °C) (see Cold hardiness)
Light and soil: in the wild, hill forest, often in shaded understorey, on deep, often clayey soils; growing requirements not documented
Habit and adult size: trunk 1 to 12 m tall (up to 16 m according to Khuraijam and Singh 2020), smooth, sometimes branched; leaves 0.9 to 2.6 m long
In the UK, US and Australia: Cambridge University Botanic Garden (accession of wild origin, 2017) and three other British gardens; at least eight American gardens; no Australian garden found
Toxicity: seed extract toxic to mice at high doses; all parts of Cycas are poisonous (see Toxicity and precautions)

How to recognise Cycas pectinata

Cycas pectinata is recognised by its tall, grey, smooth trunk, free of old leaf bases, its flat leaves with narrow leaflets and its very large egg-shaped male cones, whose scales end in a long, upturned point. Two descriptions are in use, because they do not cover the same set of plants.

Lindström and Hill (2007), who still treated the species in the broad sense (from India to Vietnam), describe:

Trunk: 1 to 12 m tall and 14 to 20 cm across, with thin, smooth bark; scale leaves (cataphylls) and leaf bases do not persist;
Leaves: 30 to 40 in the crown, dark green to grey-green, semi-glossy, 150 to 240 cm long, flat, with 180 to 312 leaflets; petiole 30 to 80 cm;
Median leaflets: 20 to 31.5 cm long and 7.5 to 10.5 mm wide, with slightly recurved margins;
Male cones: egg-shaped, yellow or green, 30 to 55 cm long and 16 to 22 cm across; firm scales ending in a point 17 to 32 mm long;
Megasporophylls: 22 to 30 cm, covered in grey down, bearing 2 to 4 ovules; rounded blade deeply cut into 40 to 50 soft spines, with a distinct terminal spine 3.5 to 7.5 cm long;
Seeds: flattened-ovoid, 42 to 45 mm; yellow sarcotesta containing a fibrous layer; no spongy layer.

For the plants west of the Indo-Burmese ranges only, Khuraijam and Singh (2020) give slightly different figures: trunk up to 16 m, branched or not; leaves 90 to 264 cm with 100 to 230 pairs of leaflets 13 to 22 cm long and 6 to 12 mm wide; male cones 24 to 62 cm; megasporophylls 11 to 25 cm bearing 1 to 5 ovules; seeds 3.4 to 5.2 cm, yellow turning orange to orange-red. The character they use to separate the two species lies on the scales of the male cone: in Cycas pectinata the upper face carries a thickened bump, which is missing in Cycas divyadarshanii, whose scales are also longer and narrower.

Hybrids

No natural or garden hybrid of Cycas pectinata is known. In China, Zheng and colleagues (2025) found no genetic mixing, in adults or in seedlings, between plants they call Cycas pectinata and Cycas simplicipinna, which grow together in Xishuangbanna and the Pu’er region of Yunnan. The two remain apart because they cone at different times, have different pollinators and grow at different positions on the slopes and on soils of different pH. According to The World List of Cycads, however, these Yunnan populations belong to Cycas divyadarshanii.

Possible confusion

The main risk of confusion today is with Cycas divyadarshanii, the species split off in 2020. The two look very much alike; only the male cones separate them with certainty, and provenance helps: west of the Brahmaputra and Barak valleys the plant is Cycas pectinata, while in Manipur, Myanmar, Thailand, Laos, Vietnam and Yunnan it is Cycas divyadarshanii according to The World List of Cycads. On the French forum Fous de palmiers, a grower who in 2013 had shared seed “of Cycas pectinata” collected in Myanmar explained in 2019 and again in 2020 that it was in fact Cycas divyadarshanii. Plants and seed sold in Europe and North America under the name Cycas pectinata often come from South-East Asia, so their identity needs checking.

Other species can also be mistaken for it:

Cycas siamensis, from Indochina, which is smaller and has a swollen trunk base;
Cycas clivicola and Cycas elongata, which share the thin, smooth bark that Lindström and Hill (2007) attribute to the rapid decay of leaf bases in humid climates;
Cycas hongheensis, from Yunnan, with a similarly tall, smooth trunk but keeled leaves covered in a rather persistent white down, a feature that sets it apart from the whole group according to Hill (2008);
Cycas circinalis, from southern India, of which Schuster made Cycas pectinata a variety in 1932; its megasporophylls are not cut like a comb.

Taxonomy

Cycas pectinata is accepted by The World List of Cycads. The World Checklist of Vascular Plants (WCVP), on which POWO is based, also accepts Cycas divyadarshanii but gives it only Assam, and still includes Bangladesh, Nepal, the eastern Himalaya, Myanmar, south-central China, Thailand, Laos, Cambodia and Vietnam in the range of Cycas pectinata (consulted through GBIF on 31 October 2026).

The species was described in 1826 by the Scottish surgeon and botanist Francis Buchanan-Hamilton in the Memoirs of the Wernerian Natural History Society (5(2): 322–323), from plants of the “hills bordering Bengal to the east” and of the forests of Kamrup, in Assam. No specimen was cited. De Laubenfels and Adema (1998) designated as lectotype a specimen collected by Hooker and Thomson at Chittagong in 1855; Lindström and Hill (2007) point out that it is in fact a neotype, since it was gathered after publication. In 2018 Khuraijam and colleagues proposed conserving the name with a new type collected in Kamrup in 2008; the outcome of the proposal has not been checked, and The World List of Cycads still shows the Chittagong type.

The name has often been wrongly credited to William Griffith (1854), who merely redescribed the species; Griffith did, however, publish Cycas jenkinsiana, from a plant from Assam, now a synonym. Schuster (1932) reduced it to a variety of Cycas circinalis. Lindström and Hill (2007) and Hill (2008) treated Cycas pectinata as a very widespread species, from the Himalaya to Vietnam, while noting that it headed a group of related species.

In 2020 Jibankumar Singh Khuraijam and Rita Singh published a morphometric study of the Indian populations (Cycads 5(1): 59–76). In their view, Cycas pectinata is confined to the west of the Indo-Burmese ranges, separated by the Barak and Brahmaputra valleys from the populations further east, which they describe as a new species, Cycas divyadarshanii, with a type from Manipur. They base the split on the male cone scales, leaflet anatomy, pollen and different pollinating beetles: Cycadophila assamensis, found only on the Cycas pectinata of Assam, and Cycadophila yunnanensis, found on the Cycas divyadarshanii of Manipur as on South-East Asian cycads. The World List of Cycads has adopted the split. It is not followed everywhere: in 2025 a team from the Kunming Institute of Botany still called the Yunnan plants Cycas pectinata. For the reader, this means that a plant from Thailand, Myanmar or Vietnam sold as Cycas pectinata is, according to the reference list, a Cycas divyadarshanii.

Cycas calcicola, an Australian species, was never included in Cycas pectinata.

Etymology and history

The epithet comes from the Latin pectinatus, “comb-like”, referring to the long teeth of the megasporophylls (Haynes 2022, cited by The World List of Cycads; Lindström and Hill 2007).

Francis Buchanan-Hamilton (1762–1829) served as a surgeon in the Bengal Medical Service from 1795 to 1815, and was superintendent of the Calcutta botanic garden in 1814–1815 (Lindström and Hill 2007). According to these authors, Cycas pectinata was the fourth species of Cycas to be named. Hossain and colleagues (2021) report that William Griffith had seen the species as early as 1838 in the Baroiyadhala forest near Chattogram (Bangladesh). No reliable information has been published on its introduction into cultivation in Europe or North America.

Common names

There is no established English name. A Mississippi State University extension publication (Maddox and Kelly, 2022) lists it as “pectinate sago palm”, a descriptive name that has not been found in floras. The following local names are published:

Assamese: thaljimura (Lindström and Hill 2007; Species+), nagphal, nagchampa, ak phal (Khuraijam and Singh 2020);
Khasi (Meghalaya): dieng-sia-goda (Lindström and Hill 2007; Khuraijam and Singh 2020);
Nepali: thakal, thaljimura (Lindström and Hill 2007); jaggar in Nepal and thakal in Sikkim according to Khuraijam and Singh (2020);
Tharu (Bihar): khu-tha; Bhutan: bango-shing (Khuraijam and Singh 2020);
Chinese: bi-chi su-tie (“cycad with comb-like megasporophylls”), feng-wei-jiao, feng-huang-dan (Lindström and Hill 2007; Hill 2008; Species+).

The Chinese, Burmese (môndaing) and Thai names (boka, plong, prong khao, prong pa) recorded for Cycas pectinata in the broad sense apply, under the current classification of The World List of Cycads, to plants now placed in Cycas divyadarshanii; Khuraijam and Singh (2020) indeed give the names yendang (Manipuri) and mondang (Burmese) for Cycas divyadarshanii.

In the wild

As defined by The World List of Cycads, Cycas pectinata grows in Bangladesh, Bhutan, Nepal and north-east India (Assam, Bihar, Meghalaya, Sikkim, West Bengal). The sources describe its habitats in different ways:

Lindström and Hill (2007): common in the hill forests of the south-eastern Himalaya, mostly above about 500 m, in the understorey of medium to tall forest, on deep, often clayey and fertile soils, in moderate to deep shade; often on limestone, but also on granite and metamorphic rocks;
Khuraijam and Singh (2020): warm deciduous forest between 52 and 250 m; in Bhutan, hillsides with pines up to 1,300 m; in Nepal, sal forest (Shorea robusta) between 300 and 730 m;
Tobgay and colleagues (2023): in Bhutan, the only Cycas in the country, found at two sites, on steep ground in open chir pine forest;
Hossain and colleagues (2021): in Bangladesh, confined to a few hills of Baroiyadhala National Park (Sitakunda, Chattogram district).

The difference between these descriptions probably reflects, in part, how the species was delimited: Lindström and Hill’s description also covered the populations of Indochina.

Conservation status and regulation

Cycas pectinata is listed as Vulnerable on the IUCN Red List, under criteria A2cd+4cd according to The World List of Cycads. The current assessment, by J. D. Bösenberg, was published in the Red List in 2023 (Crossref; category confirmed by GBIF); it follows an assessment by Nguyen in 2010, already Vulnerable, which covered the species in the broad sense. The Red List itself could not be consulted, so it has not been possible to check whether the 2023 assessment applies the 2020 split. Cycas divyadarshanii has not been evaluated (The World List of Cycads); Khuraijam and Singh (2020) propose Vulnerable for both species.

Recent studies describe declining populations. In Bhutan, Tobgay and colleagues (2023) cite habitat destruction and collection as an ornamental plant, together with low seed production and predation. In Bangladesh, Hossain and colleagues (2021) counted in 2018 about 12 plants and 5 seedlings per hectare at Baroiyadhala, with many dead or burnt plants; they put the decline down to habitat destruction, fire and unsustainable harvesting of leaves and of male and female cones.

Like all members of the Cycadaceae, Cycas pectinata is listed in CITES Appendix II. Species+, the official CITES and EU database, shows this as a family-level listing with annotation #4 (CoP20 version, in force since 5 March 2026), which exempts in particular seeds, pollen, and seedlings or tissue cultures obtained in vitro in sterile containers; live plants still need permits. In the European Union the species is in Annex B of Regulation (EC) No 338/97, as set by Commission Regulation (EU) 2026/1383 of 22 June 2026. Species+ still gives the species a wide range, from Nepal to Vietnam. Species+ was consulted in October 2026: check the regulations in force in your country before buying, importing or selling a plant, and ask for proof that it was raised in cultivation. This is not legal advice.

Growing Cycas pectinata

No reliable growing data have been published for Cycas pectinata in the strict sense. Most plants grown under this name in Europe and the United States were raised from seed collected in South-East Asia and are therefore probably Cycas divyadarshanii. What follows is drawn from the habitat and from the few published observations; it has not been confirmed by trials.

Outdoor and in-ground cultivation

Judging by its habitat, Cycas pectinata probably needs deep, well-drained soil, dappled light when young and a frost-free climate. Its large adult size suits it to open ground in tropical and subtropical gardens rather than to small spaces.

Container cultivation

Only young plants are practical in containers, given the size the species reaches. On the French forum Fous de palmiers, an experienced grower advised in 2014 not to let the root ball dry out in summer, and noted that the leaves can scorch in an overheated glasshouse; his plants were raised from the Burmese seed mentioned above, so probably Cycas divyadarshanii. In cool climates, a container plant has to spend the winter under frost-free glass.

In cultivation in the UK, US and Australia

The species appears in several collections, but given the confusion with Cycas divyadarshanii and the origin of most traded plants, the names on garden lists have not been checked against the 2020 split.

United Kingdom: the online catalogue of Cambridge University Botanic Garden (consulted in October 2026) lists an accession of wild origin received in 2017 (year taken from the accession number); Oxford Botanic Garden, RHS Garden Wisley and the National Botanic Garden of Wales declare the species to BGCI PlantSearch. The Royal Botanic Garden Edinburgh has shown a Cycas pectinata on its blog in its former Orchids and Cycads House, whose glasshouses are now closed for restoration. All these plants are under glass.
United States: the Huntington, the San Diego Zoo, the University of California Botanical Garden at Berkeley and five other gardens declare it to BGCI PlantSearch. A BGCI entry shows that a garden has listed the species at some point, not that a plant is alive today.
Australia: no garden is known to list it.

Propagation

Propagation is by seed. On the Fous de palmiers forum, growers who sowed the Burmese seed mentioned above in 2013–2014 reported slow and uneven germination, some seeds taking more than a year to sprout, and many empty seeds. These observations probably concern Cycas divyadarshanii. No published data specific to Cycas pectinata in the strict sense have been published.

Pests and diseases

No data specific to Cycas pectinata have been published. The known threats to the genus apply: the Asian cycad scale, Aulacaspis yasumatsui, and root rot in waterlogged compost. In Europe, the EPPO database (update of 16 October 2026) lists the scale as present, with few occurrences, in several countries including the United Kingdom. The resistance to scale sometimes credited to the species on American forums rests on an isolated, unverifiable comment about plants of unknown origin.

Cold hardiness

No reliable measured data exist for Cycas pectinata in the strict sense, and no outdoor result has been documented in Europe: the only French report found, a plant in Corse-du-Sud dug up by wild boar in 2013, gives no temperature and its identity cannot be checked.

In the United States, a Mississippi State University extension publication (Maddox and Kelly, 2022) places it in USDA zone 9b and says it is “reportedly hardy to 26 °F” (−3 °C), without citing a trial; it treats the species in the broad sense (“India–SE Asia”), so the figure probably reflects plants of South-East Asian origin.

In practice, in the UK and in most of the United States and southern Australia outside the tropics, treat it as a frost-tender plant for a heated glasshouse or a frost-free conservatory.

Toxicity and precautions

The toxicity of Cycas pectinata has been documented in animals: Marak and colleagues (2023), in north-east India, tested an extract of the seeds, used locally as a remedy, in mice. At high doses the extract proved toxic, damaging the kidneys; the authors found no detectable effect at lower doses, but the study did not deal with cycasin or with human consumption and supports no conclusion about safe use.

More generally, in Cycas all parts of the plant are poisonous, the seeds most of all. They contain cycasin, which is converted in the body into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA (NC State Extension; ASPCA). In dogs, cats and horses, the ASPCA reports vomiting, sometimes bloody diarrhoea, jaundice, liver damage and fatal cases; the Pet Poison Helpline adds neurological signs.

Wear gloves to handle seeds and their fleshy coat, pick up any that fall, and keep plants and seeds out of reach of children and pets. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

Published uses mostly concern north-east India. Marak and colleagues (2023) state that the seeds are used as a remedy in parts of north-east India. Laishram and colleagues (2015) studied the fruits used by the maiba and maibi traditional healers of Manipur; in that region, under the 2020 classification, the plants belong to Cycas divyadarshanii. In Bangladesh, Hossain and colleagues (2021) describe the harvesting of leaves and cones without specifying their use. Other food uses (seeds, young leaves, starch from the trunk) circulate on encyclopaedic websites without a verified primary source; they are not repeated here. These preparations must not be copied.

Frequently asked questions

Does Cycas pectinata grow in Thailand and Vietnam?

No, according to The World List of Cycads. Since 2020 the populations of South-East Asia, Yunnan and Manipur have been placed in Cycas divyadarshanii, and Cycas pectinata is restricted to Nepal, Bhutan, Bangladesh and north-east India. Some databases, including Species+, still use the wider range.

How does it differ from Cycas divyadarshanii?

Mainly in the male cones. In Cycas pectinata the cone scales carry a thickened bump on their upper face; in Cycas divyadarshanii they are longer and narrower, without this bump. For a plant without cones, provenance is the best clue.

Is Cycas pectinata hardy?

Not in any useful sense. No measurement or reliable growing report exists for the species in the strict sense; an American extension publication gives it as “reportedly hardy to 26 °F” (−3 °C), for plants that are probably of South-East Asian origin. In the UK it needs frost-free glass.

How big does it get?

Large. The trunk reaches 1 to 12 m according to Lindström and Hill (2007), and up to 16 m according to Khuraijam and Singh (2020), with leaves 0.9 to 2.6 m long.

Is Cycas jenkinsiana a different species?

No. That name, published by Griffith in 1854 from a plant from Assam, is a synonym of Cycas pectinata.

Is it endangered?

Yes, it is listed as Vulnerable by the IUCN, and recent studies in Bhutan and Bangladesh show small populations threatened by habitat destruction, fire and harvesting.

Is it poisonous?

Yes. Its seeds proved toxic to mice at high doses, and all parts of Cycas are poisonous to people and animals.

Sources

Reference sites

The World List of Cycads (version 2026.08.15), Cycas pectinata: https://cycadlist.org/scientific_name/183 — accepted name, author, protologue, Chittagong lectotype, range restricted to Bangladesh, Bhutan, India and Nepal, synonyms, IUCN status VU A2cd+4cd, etymology. Checklist of the IUCN Cycad Specialist Group, reliable; consulted on 2 and 21 October 2026.
The World List of Cycads (version 2026.08.15), Cycas divyadarshanii: https://cycadlist.org/scientific_name/892 — species split off in 2020, type from Manipur, range (China, India, Laos, Myanmar, Thailand, Vietnam), not evaluated by the IUCN; gives access to the text of Khuraijam and Singh (2020). Checklist of the IUCN Cycad Specialist Group, reliable; consulted on 2 and 21 October 2026.
Species+ (UNEP-WCMC), Cycas pectinata: https://speciesplus.net/species#/taxon_concepts/21005/legal — CITES Appendix II (family listing, annotation #4, CoP20 version of 5 March 2026) and EU Annex B (Regulation (EU) 2026/1383); local names and a wide range (nine countries). Official CITES and EU database, reliable; consulted in October 2026.
GBIF (API), Cycas pectinata: https://api.gbif.org/v1/species/2683250/iucnRedListCategory — current IUCN Red List category (VU). Reference data infrastructure; consulted on 21 October 2026.
GBIF, World Checklist of Vascular Plants (Cycas divyadarshanii): https://api.gbif.org/v1/species/209722731/distributions — accepted name in the World Checklist of Vascular Plants (basis of POWO), range: Assam. Kew data distributed by GBIF, reliable; consulted on 31 October 2026.
GBIF, World Checklist of Vascular Plants (Cycas pectinata), distribution: https://api.gbif.org/v1/species/206945296/distributions — range of Cycas pectinata in the World Checklist of Vascular Plants: Assam, Bangladesh, Cambodia, south-central China, eastern Himalaya, Laos, Myanmar, Nepal, Thailand, Vietnam. Kew data distributed by GBIF, reliable; consulted on 31 October 2026.
Journal of Threatened Taxa, Tobgay et al. (2023): https://threatenedtaxa.org/index.php/JoTT/article/view/7809 — populations, habitat and threats in Bhutan. Open-access scientific journal.
Journal of Threatened Taxa, Hossain et al. (2021): https://threatenedtaxa.org/index.php/JoTT/article/view/5922 — density, threats and Griffith’s observation of 1838 in Bangladesh. Open-access scientific journal.
Mississippi State University Extension, Palms & Cycads for the Midsouth Landscape (Publication 2948): https://extension.msstate.edu/publications/palms-cycads-for-the-midsouth-landscape — name “pectinate sago palm”, USDA zone 9b, “reportedly hardy to 26 °F”, range given in the broad sense. University extension service; a compilation without trials, to be read as an indication; consulted on 21 October 2026.
Cambridge University Botanic Garden, Living Collections Portal: https://www.botanic.cam.ac.uk/collections/collectionsportal/ — Cycas pectinata, accession of wild origin (2017). Garden’s own catalogue, reliable for presence; consulted in October 2026.
Royal Botanic Garden Edinburgh, Botanics Stories, “Orchids and Cycads House”: https://stories.rbge.org.uk/archives/category/orchids-cycads-house — photograph of Cycas pectinata in the former glasshouse. Garden blog, reliable for presence at the time; consulted in October 2026.
BGCI PlantSearch: https://plantsearch.bgci.org/ — gardens declaring the species (4 in the United Kingdom, 8 in the United States, none in Australia). Global database of garden lists, undated per garden: a listing does not prove a living plant; consulted in October 2026.
EPPO Global Database, Aulacaspis yasumatsui: https://gd.eppo.int/taxon/AULSYA/distribution — distribution of the scale insect in Europe (update of 16 October 2026). Intergovernmental organisation, reliable; consulted on 21 October 2026.
Fous de palmiers forum (France), threads “Qui veut des graines de Cycas pectinata?” (t=16231) and “Cycas rencontrés au Bhoutan…” (t=11959): https://www.fousdepalmiers.fr/html/forum/ — Burmese seed later identified as Cycas divyadarshanii (2019–2020), glasshouse growing advice (2014), slow germination, cycads seen in Bhutan (2012). Growers’ forum, amateur observations of indicative value; cited anonymously.
NC State Extension Plant Toolbox, Cycas revoluta: https://plants.ces.ncsu.edu/plants/cycas-revoluta/ — cycasin present in all parts of the plant. University extension service, reliable; genus-level information.
ASPCA Animal Poison Control, Sago Palm: https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/sago-palm — toxicity of cycads to dogs, cats and horses, cycasin, symptoms. Veterinary poison control centre, reliable; genus-level information.
Pet Poison Helpline, Sago Palm: https://www.petpoisonhelpline.com/poison/sago-palm/ — digestive, neurological and liver signs in animals. Veterinary poison control centre, reliable; genus-level information.

Bibliography

Buchanan-Hamilton, F. (1826). Commentary on the Herbarium Amboinense. Memoirs of the Wernerian Natural History Society 5(2): 322–323. [Protologue; reference taken from The World List of Cycads.]
Griffith, W. (1854). Notulae ad Plantas Asiaticas 4: 9–10. Bishop’s College Press, Calcutta. [Publication of Cycas jenkinsiana; reference taken from The World List of Cycads and Lindström and Hill (2007).]
de Laubenfels, D.J. & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [Designation of the Chittagong type; reference taken from The World List of Cycads.]
Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. doi:10.7751/telopea20075745 [Description, history, typification, local names, habitat and status; peer-reviewed article.]
Hill, K.D. (2008). The genus Cycas (Cycadaceae) in China. Telopea 12(1): 71–118. doi:10.7751/telopea20085804 [Same treatment for China, Chinese names, place in the species group.]
Khuraijam, J.S., Singh, R., Calonje, M. & Mazumdar, J. (2018). (2653) Proposal to conserve the name Cycas pectinata (Cycadaceae) with a conserved type. Taxon 67(6): 1213. doi:10.12705/676.22 [Proposed conserved type; reference checked on Crossref, outcome not checked.]
Khuraijam, J.S. & Singh, R. (2020). Taxonomic status of the Cycas pectinata complex. Cycads 5(1): 59–76. [Split of Cycas divyadarshanii, descriptions, habitats, local names, pollinators; proceedings of the 10th International Conference on Cycad Biology, copy on The World List of Cycads.]
Nguyen, H.T. (2010). Cycas pectinata. The IUCN Red List of Threatened Species 2010: e.T42062A10617695. doi:10.2305/IUCN.UK.2010-3.RLTS.T42062A10617695.en [Earlier assessment (VU), species in the broad sense; reference checked on Crossref.]
Bösenberg, J.D. (2023). Cycas pectinata. The IUCN Red List of Threatened Species 2023: e.T42062A69154502. doi:10.2305/IUCN.UK.2023-1.RLTS.T42062A69154502.en [Current assessment (VU); reference checked on Crossref, category checked on GBIF.]
Hossain, M.K., Hossain, M.A., Hossain, S., Rahman, M.R., Hossain, M.I., Nath, S.K. & Siddiqui, M.B.N. (2021). Status and conservation needs of Cycas pectinata Buch.-Ham. in its natural habitat at Baroiyadhala National Park, Bangladesh. Journal of Threatened Taxa 13(8): 19070–19078. doi:10.11609/jott.5922.13.8.19070-19078 [Densities, threats; peer-reviewed article.]
Tobgay, S., Wangdi, T., Wangchuck, K., Dolkar, J. & Nidup, T. (2023). Assessment of population, habitat, and threats to Cycas pectinata Buch.-Ham. (Cycadaceae), a vulnerable cycad in Bhutan. Journal of Threatened Taxa 15(3): 22866–22873. doi:10.11609/jott.7809.15.3.22866-22873 [Bhutan; peer-reviewed article.]
Zheng, F., Wang, Y., Xi, H., Xiao, S., Feng, X., Gong, X. & Liu, J. (2025). Ecological isolation maintains the species boundaries between two sympatric Cycas from Southwest China. Ecology and Evolution 15(7): e71769. doi:10.1002/ece3.71769 [No hybridisation with Cycas simplicipinna in Yunnan; plants placed in Cycas divyadarshanii by The World List of Cycads.]
Marak, C.C., Marak, B.N., Singh, V.P., Gurusubramanian, G. & Roy, V.K. (2023). Phytochemical analysis, in silico study and toxicity profile of Cycas pectinata Buch.-Ham seed in mice. Drug and Chemical Toxicology 46(2): 330–342. doi:10.1080/01480545.2022.2033258 [Toxicity of seed extract in mice.]
Laishram, S., Sheikh, Y., Moirangthem, D.S. et al. (2015). Anti-diabetic molecules from Cycas pectinata Griff. traditionally used by the Maiba-Maibi. Phytomedicine 22(1): 23–26. doi:10.1016/j.phymed.2014.10.007 [Use by the healers of Manipur.]
Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology of the epithet; cited by The World List of Cycads.]
Maddox, V. & Kelly, L. (2022). Palms & Cycads for the Midsouth Landscape. Publication 2948 (POD-05-22), Mississippi State University Extension Service. [Name “pectinate sago palm”, zone and reported hardiness; extension compilation.]
Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. doi:10.5281/zenodo.21958524 [Reference checklist: accepted name, authors, protologue, type, range, synonyms, IUCN status.]