Cycas bifida

Cycas bifida is a trunkless cycad of southern Guangxi, in China, and north-eastern Vietnam, where it grows in scrubby woodland on and around karst limestone outcrops. First described in 1902 as a variety of Cycas rumphii (Cycas rumphii var. bifida) and long confused with Cycas micholitzii, this member of the genus Cycas owes its name to its forked leaflets, which divide dichotomously close to the base. It has been treated as a species since 2004, and the IUCN classes it as Vulnerable (2022).

Key facts about Cycas bifida

  • Accepted name: Cycas bifida (Dyer) K.D.Hill (2004), 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 rumphii var. bifida Dyer (1902), the basionym; long treated in China as Cycas micholitzii (see Taxonomy)
  • Family: Cycadaceae, order Cycadales; section Stangerioides
  • Common names: no English name attested; in Chinese long-kou su-tie and cha-ye su-tie, “fork-leafed cycad” (Hill 2008)
  • Natural range: southern Guangxi (China) and north-eastern Vietnam (Cao Bang, Lang Son and Tuyen Quang provinces)
  • IUCN status: Vulnerable (VU A2cd), assessed by J. D. Bösenberg in 2022
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no measured threshold; in laboratory tests it proved less tolerant of freezing than Cycas panzhihuaensis (see Cold hardiness)
  • Light and soil: low, fairly dense mixed evergreen and deciduous or bamboo woodland, often on red terra rossa soils around steep limestone outcrops, also on loamy soils over shales
  • Habit and adult size: underground stem 10 to 30 cm across; 2 to 5 leaves 2 to 5 m long
  • In the UK, US and Australia: grown at Montgomery Botanical Center (accessions of 1994) and Fairchild (2021) in Florida; listed by several Californian and Hawaiian gardens and by James Cook University (Townsville) in BGCI PlantSearch; no record in Britain
  • Toxicity: no analysis specific to the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas bifida

It is recognised at once by its very long leaves, carried on long spiny petioles straight from the ground, whose leaflets fork dichotomously very near their base. Ken Hill (2008) points out, however, that forked leaflets also occur in related species and in a horticultural form of Cycas revoluta popular in Japan; within its group, Cycas bifida is distinguished by its long leaves with glossy, thin-textured, comparatively long and broad leaflets divided very close to the base. His description:

  • Stem: underground (acaulescent), 10 to 30 cm in diameter at the narrowest point; 2 to 5 leaves in the crown.
  • Leaves: bright green, semi-glossy, 200 to 500 cm long, slightly keeled to flat in section, with 40 to 80 leaflets and white and orange felt that falls as the leaf expands; the rachis usually ends in a pair of leaflets.
  • Petiole: 110 to 160 cm (35 to 50 % of the leaf), hairless, spiny for 90 to 100 % of its length, with spines 1 to 6 mm long.
  • Median leaflets: dichotomously branched up to three times, strongly two-toned, 300 to 600 mm long and 18 to 25 mm wide, set at 45 to 70° to the rachis and 60 to 95 mm apart, narrowed to 3 to 4 mm at the base; flat, with flat margins; tip softly acuminate, not spiny.
  • Cataphylls: narrowly triangular, soft, hairy, 55 to 90 mm long.
  • Male cones: spindle-shaped, yellow or cream, 35 to 55 cm long and 6 to 8 cm across; microsporophylls soft, without an apical spine.
  • Megasporophylls: 7 to 11 cm long, brown-felted, bearing 2 to 6 hairless ovules; blade ovate, 35 to 100 mm long, deeply comb-like, with 12 to 15 soft lateral spines 18 to 50 mm long.
  • Seeds: flattened-ovoid, 25 mm long and 20 mm wide; sarcotesta yellow, 2 mm thick, without a fibrous layer; sclerotesta warty.

Hybrids

Natural hybrids are well documented. Hill (2008) describes ranges of intermediate forms, interpreted as hybrid swarms, where Cycas bifida grows close to Cycas multipinnata in Yunnan, and a sight record of intermediates with Cycas dolichophylla north-west of Thai Nguyen, in Vietnam. Two names published by Wang in 1996 rest on such plants, according to Hill: Cycas longipetiolula (bifida × multipinnata) and Cycas multifrondis (bifida × dolichophylla, described from a plant grown at Xiamen Botanical Garden); The World List of Cycads nevertheless accepts Cycas multifrondis as a species. Plants grown at Shenzhen Fairy Lake Botanical Garden are thought to be hybrids between Cycas bifida and Cycas diannanensis, but no specimen vouches for them (Hill 2008).

A RADseq study of six Cycas species from southern China (Tao and colleagues, Frontiers in Genetics, 2021) also found substantial genetic admixture between Cycas dolichophylla and, among others, Cycas bifida. In practice, plants sold as Cycas bifida may therefore carry genes from neighbouring species.

Possible confusion

Several cycads of the China–Vietnam border region have divided leaflets. In Hill’s key to the Chinese species (2008):

  • Cycas multipinnata and Cycas debaoensis have leaflets that are themselves pinnately divided, whereas those of Cycas bifida are only forked; Cycas multipinnata has just 1 or 2 leaves up to 6 m long, Cycas debaoensis 3 to 15 leaves up to 3 m with long-tapering segments.
  • Cycas micholitzii, from central Vietnam and Laos, is the most similar species; Cycas bifida differs in its larger size, its longer, broader, laxer and glossier leaflets and its larger male cones with mostly spineless microsporophylls.
  • A horticultural form of Cycas revoluta popular in Japan also has forked leaflets (Hill 2008), but Cycas revoluta forms a trunk and has rigid leaflets with rolled-under margins and felted ovules.

Taxonomy

Cycas bifida is an accepted species in section Stangerioides, the group of mostly trunkless Asian Cycas with soft male cones, a loose, freely peeling sarcotesta without a fibrous layer and a warty seed shell. The World Checklist of Vascular Plants (WCVP), on which POWO is based, also accepts it (consulted through GBIF on 31 October 2026).

The name has a complicated history. William Thiselton-Dyer described Cycas rumphii var. bifida in 1902 from a leaf fragment collected by H. B. Morse in 1896 in the Longzhou district of southern Guangxi (holotype at Kew). In 1905 he described Cycas micholitzii from material collected in Annam, central Vietnam, noting the resemblance to his variety without combining the two. Later authors, including the Flora of China (Chen and Stevenson 1999), treated all these plants as Cycas micholitzii. Ken Hill, with Nguyen Tien Hiep and Phan Ke Loc, raised the Guangxi and northern Vietnamese plants to species rank as Cycas bifida in their revision of the genus in Vietnam (The Botanical Review, 2004), and Hill confirmed the distinction in his Chinese revision of 2008. For readers, this means that older Chinese literature and some plant labels using Cycas micholitzii may refer to Cycas bifida.

Etymology and history

The epithet comes from the Latin bifidus, “cleft in two” or “forked”, referring to the dichotomously divided leaflets (Hill 2008; Haynes 2022). The type, Morse 273, was collected in December 1896 on the “Lighthouse pagoda rockhills” at Lungchow (Longzhou); it consists of two sheets at Kew. Hill (2008) also cites cultivated plants of known wild origin: in a nursery of the Nanning Forestry Research Centre and in a city park at Longzhou, both from Longzhou county, and in a garden in Tuyen Quang province, Vietnam.

Common names

No English common name is attested; “fork-leafed cycad” is Hill’s translation of a Chinese name, not an established English name. Hill (2008) records two Chinese names, long-kou su-tie and cha-ye su-tie, the latter meaning “fork-leafed cycad”.

In the wild

According to Hill (2008), Cycas bifida grows in southern Guangxi and north-eastern Vietnam, in low, scrubby but fairly dense mixed evergreen and deciduous or bamboo woodland, often on red terra rossa soils on and around steep karst limestone outcrops, but also on loamy soils over shales and metasandstones. It is locally abundant, but many populations are now depleted. The World List of Cycads gives its range as Guangxi in China and the provinces of Cao Bang, Lang Son and Tuyen Quang in Vietnam; Hill also cites one specimen from Hekou county, in Yunnan, close to the Vietnamese border.

Its roots have been studied in detail. A 2018 study using next-generation sequencing (Zheng and colleagues, Journal of Microbiology) found highly diverse communities of bacteria and fungi in both the coralloid roots and the ordinary roots, with cyanobacteria, the nitrogen-fixing partners of cycads, more dominant in the coralloid roots.

Conservation status and regulation

Cycas bifida is classed as Vulnerable (VU A2cd) on the IUCN Red List, in the assessment by J. D. Bösenberg published in 2022 (category checked through GBIF); the previous assessment, by Nguyen Tien Hiep, dated from 2010. Hill (2008) reports that numbers have been severely reduced by collecting and by unrestrained agricultural and forestry development, and that its rarity and unusual habit make it highly sought after by collectors; it was nevertheless still frequent in many places, especially in Vietnam, and not considered at risk in the short term. Before the species was separated, it was treated in the 1997 IUCN Red List as Cycas micholitzii, Endangered for China.

Like every species in the genus except Cycas beddomei, Cycas bifida is listed in CITES Appendix II, where the family Cycadaceae has been included since 4 February 1977. The listing carries annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are not covered by CITES, whereas international trade in plants requires an export permit. The United Kingdom, the United States and Australia apply CITES through their own national legislation; in the European Union the species is in Annex B of Regulation (EC) No 338/97, whose annexes in force are set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+, the official CITES database, confirms this status (consulted on 19 October 2026).

This general information does not replace the official texts: check the rules in force before any purchase or exchange, ask the seller for proof of origin and prefer plants raised from seed in cultivation.

Growing Cycas bifida

In short: a striking but large plant for a warm garden or a big glasshouse, best grown from nursery-raised seedlings of known origin; no institution has published detailed growing guidance for it. The species is, however, grown in several American botanic gardens (see below), and Hill (2008) mentions plants grown in a park, a nursery and a garden in China and Vietnam.

Its habitat gives the most reliable pointers: dense woodland, which suggests protection from the harshest sun, and very free-draining soils, often of limestone origin, but also on shale. These are inferences from the habitat, not results of published trials. The size of the leaves, which reach 2 to 5 m in the wild, needs to be taken into account when choosing a site.

Outdoor and in-ground cultivation

The species is grown in South Florida: Montgomery Botanical Center, whose collections are grown outdoors, holds three accessions, and Fairchild Tropical Botanic Garden lists it in its living collection catalogue. No published result describes how it behaves outdoors in a Mediterranean climate, in temperate Australia or in Britain. Its long leaves on slender petioles suggest a site sheltered from strong wind, but this is a deduction rather than a documented observation.

Container cultivation

No experience of container growing is published. A young plant, whose leaves are much shorter than an adult’s, can be kept in a deep pot with a very free-draining mix and bright, filtered light; in a cool climate it needs a frost-free glasshouse in winter. These recommendations follow from its habitat and from its lower tolerance of freezing compared with Cycas panzhihuaensis in laboratory tests (see Cold hardiness), not from cultivation reports.

In cultivation in the UK, US and Australia

In short: Cycas bifida is present in several American public collections, in Florida, California and Hawaii, in one Australian university garden, and in no British garden on the records found. A garden listed in the BGCI PlantSearch database (consulted in October 2026) has declared the species at some point, which does not prove that a living plant is there today.

  • United States: Montgomery Botanical Center (Coral Gables, Florida) lists three accessions in its online catalogue, whose numbers point to 1994; Fairchild Tropical Botanic Garden (Coral Gables) lists one accession of 2021 in its Garden Explorer (updated 16 October 2026). BGCI PlantSearch also lists the species for the Huntington (San Marino, California), the University of California Botanical Garden at Berkeley, Sonoma Botanical Garden (Glen Ellen, California) and the botanical garden of the University of Hawaii at Hilo.
  • Australia: James Cook University (Townsville, Queensland) lists the species in BGCI PlantSearch.
  • United Kingdom: no British garden lists the species.

No report from a grower in the United Kingdom, the United States or Australia has been published on English-language forums.

Propagation

Like all Cycas, Cycas bifida is dioecious: a male and a female plant are needed to obtain fertile seed. No germination data specific to the species is documented, and no account of propagation from offsets. Seeds are exempt from CITES under annotation #4; ask for seed collected from cultivated plants, and bear in mind that seed from mixed collections may be of hybrid origin (see Hybrids).

Pests and diseases

No pest or disease specific to the species is documented. Scale insects, including Aulacaspis yasumatsui, threaten all cultivated Cycas, but no attack on this species in particular has been reported.

Cold hardiness

There is no measured outdoor threshold for Cycas bifida. Two Chinese laboratory studies give a relative answer: plants exposed to low and freezing temperatures showed a marked drop in photosynthetic activity, which fell to zero after recovery, and their membrane lipids were more disrupted than those of Cycas panzhihuaensis, the reference species for cold tolerance in the genus (Zheng and colleagues, BMC Plant Biology, 2021); the same contrast was found under unexpected freezing (Wu and colleagues, Frontiers in Plant Science, 2023). In other words, Cycas bifida is clearly less frost-tolerant than Cycas panzhihuaensis, but these studies do not give a usable garden temperature.

No USDA zone for the species is given by a reliable source, and no dated frost episode in cultivation is documented, in Europe, the United States or Australia. The Jardin zoologique tropical in the south of France has published no observation of it. Until growers’ results are published, treat it as frost-tender and keep it frost-free.

Toxicity and precautions

No toxicity analysis specific to Cycas bifida is documented, but the risk is well documented in the genus: Cycas tissues, and the seeds above all, contain cycasin, which is converted during digestion into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA. The ASPCA lists Cycas revoluta among plants poisonous to dogs, cats and horses. Treat the plant as poisonous: keep seeds and leaves out of reach of children and pets, and wear gloves to clean the seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No traditional use specific to Cycas bifida is documented. Hill (2008) notes that its rarity and unusual habit make it highly prized by collectors, and cites plants grown in a city park, a forestry nursery and a garden in Guangxi and Vietnam.

Frequently asked questions

Why are the leaflets of Cycas bifida forked?

Because they divide dichotomously, close to the base, up to three times according to Hill (2008); the name bifida means “forked”. The feature is shared with a few related Chinese and Vietnamese species and with a horticultural form of Cycas revoluta popular in Japan.

How is it different from Cycas micholitzii?

It is larger, with longer, broader, laxer and glossier leaflets and larger male cones whose scales are mostly spineless; Cycas micholitzii grows in central Vietnam and Laos. The two were treated as one species until Hill’s revisions of 2004 and 2008.

Is Cycas bifida the same as Cycas multipinnata or Cycas debaoensis?

No. In those two species the leaflets are themselves pinnately divided, whereas in Cycas bifida they are only forked. Hybrid swarms with Cycas multipinnata exist in the wild, however.

Is it frost-hardy?

Not on present evidence. No outdoor threshold has been measured, and laboratory studies show it tolerates freezing much less well than Cycas panzhihuaensis; keep it frost-free.

Can it be grown outdoors in the UK?

There is no evidence that it can. No outdoor result has been published outside warm climates; in Britain, grow it in a heated glasshouse or conservatory with room for its long leaves.

Is it threatened?

Yes. The IUCN classes it as Vulnerable (2022), because collecting and land clearance have depleted many populations, although it remains locally frequent, especially in Vietnam.

Is it poisonous?

Yes, it should be treated as such. There is no analysis of this species, but every Cycas studied contains toxins dangerous to people and animals, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Thiselton-Dyer, W.T. (1902). Cycas rumphii var. bifida. Journal of the Linnean Society, Botany 26: 560. [Basionym; reference taken from Hill (2008) and The World List of Cycads.]
  • Hill, K.D., Nguyen, H.T. & Loc, P.K. (2004). The genus Cycas (Cycadaceae) in Vietnam. The Botanical Review 70(2): 134–193. doi:10.1663/0006-8101(2004)070[0134:TGCCIV]2.0.CO;2 [Publication of the combination Cycas bifida; reference checked on Crossref.]
  • Hill, K.D. (2008). The genus Cycas (Cycadaceae) in China. Telopea 12(1): 71–118. doi:10.7751/telopea20085804 [Reference revision for China: description, key, history of the name, distinguishing features, habitat, hybrids, conservation, vernacular names.]
  • Tao, Y., Chen, B., Kang, M., Liu, Y. & Wang, J. (2021). Genome-wide evidence for complex hybridization and demographic history in a group of Cycas from China. Frontiers in Genetics 12: 717200. doi:10.3389/fgene.2021.717200 [Genetic admixture between Cycas dolichophylla and related species.]
  • Zheng, Y., Chiang, T.-Y., Huang, C.-L. & Gong, X. (2018). Highly diverse endophytes in roots of Cycas bifida (Cycadaceae), an ancient but endangered gymnosperm. Journal of Microbiology 56: 337–345. doi:10.1007/s12275-018-7438-3 [Root microbiome.]
  • Zheng, Y., Yang, Y., Wang, M. et al. (2021). Differences in lipid homeostasis and membrane lipid unsaturation confer differential tolerance to low temperatures in two Cycas species. BMC Plant Biology 21: 377. doi:10.1186/s12870-021-03158-4 [Cycas bifida less tolerant of freezing than Cycas panzhihuaensis.]
  • Wu, Y., Zhu, H., Ling, Z. et al. (2023). The metabolism of nonstructural carbohydrates, lipids, and energy in two Cycas species with differential tolerance to unexpected freezing stress. Frontiers in Plant Science 14: 1301560. doi:10.3389/fpls.2023.1301560 [Same comparison under unexpected freezing.]
  • Bösenberg, J.D. (2022). Cycas bifida. The IUCN Red List of Threatened Species 2022: e.T42059A67337100. doi:10.2305/IUCN.UK.2022-1.RLTS.T42059A67337100.en [Current assessment (VU A2cd); reference checked on Crossref, category checked through GBIF.]
  • Nguyen, H.T. (2010). Cycas bifida. The IUCN Red List of Threatened Species 2010: e.T42059A10615518. doi:10.2305/IUCN.UK.2010-3.RLTS.T42059A10615518.en [Previous assessment; reference checked on Crossref.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology; used through The World List of Cycads.]
  • 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.]