Cycas tanqingii

Cycas tanqingii is a cycad of closed evergreen forest in southern Yunnan, China, known for certain only from Lüchun County, close to the Vietnamese border, and possibly also present on the other side of that border in Vietnam. This member of the genus Cycas, described in 1996 by the Chinese botanist Wang Ding Yue, is one of the most imposing species of its group: its very glossy, dark green leaves can exceed 3.5 m in length. It is named after a former director of Fairy Lake Botanical Garden in Shenzhen. The IUCN lists it as Near Threatened.

Key facts about Cycas tanqingii

  • Accepted name: Cycas tanqingii D.Yue Wang (1996), accepted by The World List of Cycads (version 2026.08.15); POWO could not be consulted directly
  • Former names and synonyms: no synonym; the Flora of China (1999) listed it, with a question mark, among the synonyms of Cycas balansae
  • Family: Cycadaceae, order Cycadales; section Stangerioides (Hill 2008)
  • Common names: no common name attested, in English or any other language
  • Natural range: China, south-eastern Yunnan (Lüchun County, basins of the Xiaoheijiang and Heishui rivers); presence in Vietnam (Lai Chau province) reported but not backed by any specimen
  • IUCN status: Near Threatened (NT); assessment by K. D. Hill (2010, criterion B1a), then reassessment by J. D. Bösenberg published in Red List version 2023-1
  • CITES and other protection: CITES Appendix II; Annex B in the European Union; in China, all Cycas have first-class state protection
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, closed evergreen forest, sometimes secondary forest or bamboo thickets, always under a tree canopy; soil not documented
  • Habit and adult size: aerial trunk up to 2 m tall and 25 to 30 cm across, or underground trunk; leaves 1.9 to 3.6 m long
  • In the UK, US and Australia: no garden found in the UK or Australia; in the US, one garden in Hawaii declares it in BGCI PlantSearch
  • Toxicity: no analysis specific to the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas tanqingii

By its size and its leaves. In Ken Hill’s revision of the cycads of China (2008), it is the combination of a robust habit, large leaves on very long petioles, large male cones and big seeds that singles out Cycas tanqingii within section Stangerioides; in the key of the same revision, the deciding character is the distinct terminal spine of the microsporophylls, the scales of the male cone. The following description is Hill’s (2008):

  • Trunk: aerial or underground, up to 2 m tall and 25 to 30 cm across at the narrowest point; 4 to 7 leaves in the crown.
  • Leaves: 1.9 to 3.6 m long, dark green, very glossy, flat in section, with 100 to 160 leaflets; an orange felt that falls away as the leaf expands; rachis always ending in a pair of leaflets; hairless petiole 70 to 190 cm long (40 to 50% of the leaf), spiny over 90 to 100% of its length, with spines of 1 to 4 mm.
  • Median leaflets: 30 to 45 cm by 15 to 22 mm, clearly paler beneath, narrowed to 5 to 6 mm at the base, spaced 15 to 27 mm apart; margins slightly recurved; tip fine and not prickly; midrib raised on both sides.
  • Cataphylls (the scales that protect the growing point): narrowly triangular, soft, hairy, 5 to 8 cm long.
  • Male cones: spindle-shaped, yellow to orange, up to 40 cm by 5 to 8 cm; soft microsporophylls 25 to 30 mm by 10 to 13 mm, ending in a fine spine of 1.5 to 2 mm that turns abruptly upwards.
  • Megasporophylls (the fertile leaves of female plants): 10 to 12 cm long, with brown felt; 2 hairless ovules; rounded blade 50 to 55 mm by 50 to 65 mm, deeply comb-like, with 6 to 9 soft spines of 15 to 40 mm; the terminal spine is not distinct from the lateral ones.
  • Seeds: almost round to egg-shaped, 35 to 40 mm by 30 to 35 mm; fleshy coat (sarcotesta) yellow, without bloom, 2 mm thick, without a fibrous layer; warty shell (sclerotesta); no spongy layer inside, so the seeds do not float.

A contributor to the Italian forum Tropicamente described in July 2009 the reddish down on the young leaves, which then turn a glossy dark green, an observation that matches the orange felt and the shiny foliage described by Hill. Hill describes it with either an aerial or an underground trunk.

Hybrids

No hybrid, natural or in cultivation, is documented for this species.

Possible confusion

  • Cycas dolichophylla, from northern Vietnam and the far south of China: according to Hill (2008), its leaflets are shorter, more crowded, broad and rounded at the base, and its petioles shorter;
  • Cycas chevalieri, from north-central Vietnam (The World List of Cycads) and possibly neighbouring Laos, where its presence is unconfirmed according to the 2023 IUCN assessment as quoted by the English-language Wikipedia: Hill considers it perhaps the closest species, from which Cycas tanqingii differs in its generally larger stature;
  • Cycas balansae: the Flora of China included Cycas tanqingii in a broadly defined Cycas balansae; the two species are now kept apart (see Taxonomy);
  • Cycas chenii, from the upper Red River (Chuxiong and Honghe prefectures): its original description (Zhou, Guan and Gong 2015) compares it with Cycas tanqingii, but its closest relative is Cycas guizhouensis, and it is a plant without an aerial trunk.

As always in the genus, a reliable identification rests on the reproductive organs and on a documented provenance.

Taxonomy

Cycas tanqingii is accepted by The World List of Cycads; POWO could not be consulted. The species was described in 1996 by Wang Ding Yue in the multi-author book Cycads in China, edited by F. X. Wang and H. B. Liang (page 134, figure 4). The type (Wang 5538) comes from Lüchun County in Yunnan; the holotype is kept in the SZG herbarium and an isotype in the NF herbarium. IPNI and The World List of Cycads give the author as “D.Yue Wang”; Hill’s revision (2008) writes “D.Y.Yang”, probably in error.

Hill (2008) places the species in section Stangerioides, the group of Cycas with soft microsporophylls, hairless ovules and yellow seeds whose sarcotesta lacks a fibrous layer and whose shell is warty; the review by Zheng and colleagues (2017) follows the same classification.

Its status has not always been agreed. The Flora of China (Chen and Stevenson 1999) took a broad view of Cycas balansae and listed Cycas tanqingii, with a question mark, among its synonyms. In 2006 a genetic study using ISSR markers on 158 plants from all the Chinese populations of this “Cycas balansae complex” (Xiao and Gong, Annals of Botany) found five genetic groups matching the narrowly defined species, Cycas tanqingii among them, and recommended that each be conserved separately. The authors suggest that these units derive from a widespread common ancestor through several separation events, but they do not say which of them branched off first. Hill (2008) and The World List of Cycads treat Cycas tanqingii as a species in its own right.

Etymology and history

The name honours a former director of Fairy Lake Botanical Garden in Shenzhen: “Tan-Qing”, director at the time of the description according to Hill (2008), and “Dr. Tan Qing Chen” according to The World List of Cycads, which follows the etymological compendium of Haynes (2022) and acknowledges his work on cycad conservation in cultivation and research.

Hill and his colleagues collected the species on 9 July 2000 in Lüchun County, at Erpu, along the Xiaoheijiang river (and the Heishui river). For Vietnam there is only a report: according to Hill (2008), foresters in Lüchun County said that the plant also grows on the Vietnamese bank of the river, in Lai Chau province, but no herbarium specimen confirms this. The revision of the cycads of Vietnam (Hill, Nguyen and Loc 2004) nevertheless deals with the species, on pages 150 to 152 according to The World List of Cycads.

Common names

No common name is attested for this species, in English or in any other language.

In the wild

Cycas tanqingii lives in a remote, mountainous area of south-eastern Yunnan, in closed evergreen forest (Hill 2008). Zheng and colleagues (2017) list it among the Chinese species that grow in tropical forest and evergreen broadleaved forest, and also in secondary forest or bamboo thickets, always under a tree canopy, in a warm, humid monsoon climate. Like many cycads of Yunnan, it is tied to a single river basin: a 2025 study (Zheng and colleagues, Ecology and Evolution) notes, citing a 2022 study by Xi and colleagues, that it survives only in the basin of the Xiaoheijiang river in Lüchun County.

Another 2025 study (Li and colleagues, Ecological Indicators) modelled the suitable habitat of the species in the China–Laos–Vietnam region from 199 presence points (field records, GBIF and local literature). According to this model, when pests are taken into account as well as climate, the suitable area would shrink with warming from about 192,800 to about 86,200 km². These are projections, not observations.

Conservation status and regulation

The IUCN lists Cycas tanqingii as Near Threatened (NT). The World List of Cycads gives criterion B1a (restricted range) and cites Hill’s assessment of 2010; according to Crossref, the most recent assessment is by J. D. Bösenberg, published in Red List version 2023-1, and the Red List data relayed by GBIF confirm the NT category (consulted on 21 October 2026). The Red List page itself could not be consulted. The table in Hill (2008) estimates the population at more than 100,000 individuals, stable, over an area of about 100 km², with habitat reduction of less than 20%.

Sources differ on how well the species is protected in the wild. Hill’s table lists no protected area, whereas Zheng and colleagues (2017) place it in the Huanglian Mountain National Nature Reserve, in Lüchun, and describe a relatively healthy population thanks to early protection and long-term monitoring. The study by Li and colleagues (2025), by contrast, presents the species as “endangered” and sensitive to climate change and pests; this is the authors’ own wording, not an IUCN category. In China, all Cycas are on the list of plants with first-class state protection (Zheng and colleagues 2017).

Like every species in the genus except Cycas beddomei, Cycas tanqingii 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), which exempts seeds, pollen and seedlings or tissue cultures obtained in vitro in sterile containers; international trade in live plants still needs 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+ records the species in China and Vietnam and confirms this status. This general information does not replace the official texts: check the rules in force before buying or exchanging plants, ask the seller for proof of provenance and prefer plants raised from seed in cultivation.

Growing Cycas tanqingii

In short: no growing advice specific to the species has been published, and it remains rare in collections. Everything below is deduced from its habitat.

Outdoor and in-ground cultivation

No result of in-ground cultivation has been published anywhere, inside or outside China. Its natural habitat, closed, humid evergreen forest under a monsoon climate, suggests a shaded or lightly shaded position, regular watering during growth and a free-draining soil that never stays waterlogged, in a climate without frost.

Container cultivation

Outside the tropics, it is a plant for a pot kept in a bright, frost-free glasshouse or conservatory: bright but filtered light, a very free-draining mineral compost, regular watering during growth and no standing water. These are precautions deduced from the habitat, not results of trials. With leaves that can exceed 3 m, an adult plant needs a great deal of room.

In France, a few collectors mention the species on the forum Fous de palmiers: seedlings from summer 2011 raised in a glasshouse, young plants bought in 2019 and kept in pots, and, in 2013, a grower near Nantes looking for information on the hardiness of this and other Chinese Cycas. None of these messages reports a result in the open ground. The Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on this species.

In cultivation in the UK, US and Australia

In short: almost absent from public collections in these three countries. 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: the botanical garden of the University of Hawaii at Hilo declares the species in BGCI PlantSearch. It does not appear in the online catalogue of Montgomery Botanical Center.
  • Australia: no record, including in the online catalogue of the Royal Botanic Garden Sydney.
  • United Kingdom: no record.

No report from a private grower in the United Kingdom, the United States or Australia is documented.

Propagation

The plant is dioecious: a male and a female plant are needed for seed. No germination data specific to the species have been published; Cycas seeds are generally sown fresh, cleaned of their sarcotesta, in a free-draining compost and in warmth. Seeds are exempt from CITES under annotation #4; ask for seed from cultivated plants.

Pests and diseases

No disease specific to the species is documented in cultivation. In the wild, the study by Li and colleagues (2025) makes pests a decisive factor for the future of the species, without its abstract saying which ones. In cultivation, Cycas are mainly exposed to the Asian cycad scale, Aulacaspis yasumatsui, and to root rot when overwatered; these are risks documented for the genus, not for this species in particular.

Cold hardiness

There are no data on the cold tolerance of Cycas tanqingii. The species lives in evergreen forest under a warm, humid tropical to subtropical monsoon climate (Zheng and colleagues 2017): nothing suggests it can take frost.

European experience

No cultivation result has been published in Europe, in the open ground or in a pot, and no dated cold spell concerns the species. On the French forum Fous de palmiers the few plants mentioned are grown under glass or in pots, with no temperature recorded, and the Jardin zoologique tropical at La Londe-les-Maures has published no observation. Mediterranean experience therefore offers no guide for this species.

United Kingdom, United States and Australia

No cold value and no dated growing report have been published, either on the forums that could be read or from botanic gardens. Until data exist, treat the plant as frost-tender and bring it under cover as soon as frost threatens.

Toxicity and precautions

No toxicity analysis specific to Cycas tanqingii 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 the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses, with vomiting, diarrhoea and liver damage that can be fatal. In the absence of evidence to the contrary, 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 use of this species is documented.

Frequently asked questions

Where does Cycas tanqingii grow?

In southern Yunnan, China, in Lüchun County, along the Xiaoheijiang river. Its presence in neighbouring Vietnam is only reported.

Who is tanqingii named after?

A former director of Fairy Lake Botanical Garden in Shenzhen, called “Tan-Qing” by Hill (2008) and “Tan Qing Chen” by The World List of Cycads.

Does it have a trunk?

It depends on the plant. Hill describes it with an aerial trunk up to 2 m tall, or with an underground trunk.

How can it be told from Cycas dolichophylla?

By its longer, more widely spaced leaflets, which are not rounded at the base, and by its longer petioles.

Is it a synonym of Cycas balansae?

No. The Flora of China tentatively listed it among the synonyms of Cycas balansae, but a genetic study in 2006, Hill’s revision (2008) and The World List of Cycads treat it as a separate species.

Is it endangered?

Not seriously. The IUCN lists it as Near Threatened and its population is considered relatively healthy; a model published in 2025 nevertheless describes it as exposed to climate change and pests.

Can it be grown outdoors in the UK?

Almost certainly not. No cold data exist, and it lives in a warm, humid monsoon forest; grow it in a frost-free glasshouse.

Is it poisonous?

It must be assumed so. It has not been analysed, but all Cycas studied contain dangerous toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Wang, D.Y. (1996). Cycas tanqingii. In Wang, F.X. & Liang, H.B. (eds), Cycads in China: 134, fig. 4. Guangdong Science and Technology Press. [Original description; not consulted, reference taken from IPNI and The World List of Cycads.]
  • Hill, K.D. (2008). The genus Cycas (Cycadaceae) in China. Telopea 12(1): 71–118. doi:10.7751/telopea20085804 [Description (pp. 93–94), key, differences from Cycas dolichophylla and Cycas chevalieri, etymology, range, conservation table; full text consulted.]
  • Hill, K.D., Nguyen, H.T. & Loc, P.K. (2004). The genus Cycas (Cycadaceae) in Vietnam. The Botanical Review 70(2): 134–193. [Treatment of the species on pp. 150–152 according to The World List of Cycads; not consulted.]
  • Chen, C.J. & Stevenson, D.W. (1999). Cycadaceae. In Wu, Z.Y. & Raven, P.H. (eds), Flora of China 4: 1–7. Science Press, Beijing; Missouri Botanical Garden Press, St Louis. [Broad concept of Cycas balansae; consulted on eFloras.]
  • Xiao, L.-Q. & Gong, X. (2006). Genetic differentiation and relationships of populations in the Cycas balansae complex (Cycadaceae) and its conservation implications. Annals of Botany 97(5): 807–812. doi:10.1093/aob/mcl039 [Five genetic groups, Cycas tanqingii among them; abstract consulted on OpenAlex on 21 October 2026.]
  • Zheng, Y., Liu, J., Feng, X. & Gong, X. (2017). The distribution, diversity, and conservation status of Cycas in China. Ecology and Evolution 7(9): 3212–3224. doi:10.1002/ece3.2910 [Section, habitat, Huanglian Mountain reserve, state of the population; full text consulted.]
  • 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 [Range limited to the Xiaoheijiang basin, after Xi and colleagues (2022); the study itself concerns other species; full text consulted on Europe PMC.]
  • Li, J., Li, C., Yue, C. et al. (2025). Distribution patterns of suitable habitat for Cycas tanqingii in the China-Laos-Vietnam region under the interaction of climate change and pest factors. Ecological Indicators 177: 113794. doi:10.1016/j.ecolind.2025.113794 [Suitable-habitat model (MaxEnt) with climate and pests; abstract consulted on OpenAlex.]
  • Zhou, W., Guan, M.-M. & Gong, X. (2015). Cycas chenii (Cycadaceae), a new species from China, and its phylogenetic position. Journal of Systematics and Evolution 53(6): 489–498. doi:10.1111/jse.12153 [Comparison with Cycas tanqingii according to The World List of Cycads; abstract only consulted.]
  • Hill, K.D. (2010). Cycas tanqingii. The IUCN Red List of Threatened Species 2010: e.T42086A10625874. doi:10.2305/IUCN.UK.2010-3.RLTS.T42086A10625874.en [NT assessment cited by The World List of Cycads; page not consulted.]
  • Bösenberg, J.D. (2023). Cycas tanqingii. The IUCN Red List of Threatened Species 2023: e.T42086A69827277. doi:10.2305/IUCN.UK.2023-1.RLTS.T42086A69827277.en [Reassessment (2020) published in version 2023-1; reference checked on Crossref, category confirmed by GBIF; page not consulted.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology taken up by The World List of Cycads; not consulted directly.]
  • 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; consulted directly.]