Cycas dharmrajii

Cycas dharmrajii is a large cycad of the Andaman Islands, in India, described in 2017 by Lal Ji Singh, of the Botanical Survey of India, from plants in the north of the archipelago. This species of the genus Cycas is notable for a giant trunk swollen at the base that branches irregularly, and for its aerial roots. Once treated as a synonym of Cycas sainathii, itself now placed under Cycas zeylanica, it has been accepted again by The World List of Cycads since a 2020 revision; the IUCN Red List, however, still includes it in Cycas sainathii, listed as Vulnerable.

Key facts about Cycas dharmrajii

  • Accepted name: Cycas dharmrajii L.J.Singh (2017), accepted by The World List of Cycads (version 2026.08.15) and, according to a search-engine extract, by POWO, whose page could not be consulted
  • Former names and synonyms: no synonym; for a time treated as a synonym of Cycas sainathii, a treatment the IUCN Red List still follows (see Taxonomy)
  • Family: Cycadaceae, order Cycadales
  • Common names: none attested, in English or in any other language
  • Natural range: India, Andaman Islands (North Andaman, Diglipur area)
  • IUCN status: not evaluated under this name (NE) according to The World List of Cycads; the Red List includes it in Cycas sainathii, listed as Vulnerable (VU, assessment published in 2022)
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: not documented; the type was collected at 12 m above sea level
  • Habit and adult size: “giant” trunk, swollen at the base and irregularly branched; medium-sized leaves; measurements not consulted
  • In the UK, US and Australia: no garden record found
  • Toxicity: no data for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas dharmrajii

According to the abstract of the original description (Singh 2017), Cycas dharmrajii differs from all known cycads in a combination of characters:

  • a giant trunk, swollen at the base, which branches abnormally;
  • polymorphic, often branched aerial roots;
  • medium-sized leaves;
  • megasporophylls (the fertile leaves of female plants) bearing 10 to 28 pairs of well-marked, hook-shaped lateral structures, and 1 to 3 pairs of ovules;
  • two schizo-lysigenous mucilage canals in each leaflet, and characteristic pitting on the walls of the leaflet epidermal cells.

The detailed measurements (height, leaf length, cones, seeds) are given in the original article, which could not be consulted in full (paywalled): they are therefore not repeated here.

Hybrids

No hybrid is documented for this species.

Possible confusion

The World List of Cycads accepts three species in the Andaman Islands. The characters below come from their published descriptions:

  • Cycas zeylanica, a coastal cycad of Sri Lanka and the Andamans: trunk 2.3 to 3.1 m tall, barely swollen at the base; sterile blade of the megasporophylls lanceolate and obscurely toothed (6 to 12 small teeth no more than 2 mm long), according to Lindström and Hill (2007).
  • Cycas pschannae, the other large cycad of the archipelago: a tree up to 12 m tall, with a trunk not swollen at the base; sterile part of the megasporophylls triangular, with two unequal, horn-shaped lateral teeth at its base, according to its original description (Srivastava and Singh 2015).
  • Cycas dharmrajii: a giant trunk swollen at the base and unusually branched; megasporophylls with 10 to 28 pairs of hook-shaped lateral structures (abstract of Singh 2017).

The keys to the cycads of the archipelago published by Singh (2017) and by Singh and Misra (2020) could not be read, and no further distinguishing character is given here.

Taxonomy

Cycas dharmrajii is accepted by The World List of Cycads; POWO also accepts it according to a search-engine extract, its page being blocked. Lal Ji Singh, of the Andaman and Nicobar Regional Centre of the Botanical Survey of India, described it in January 2017 in the Nordic Journal of Botany (volume 35, pages 69 to 76), with a key to the Cycas of the archipelago.

Its status has changed over time. The World List of Cycads first treated it as a synonym of Cycas sainathii, another name described from the Andamans in 2014, which the list now places under Cycas zeylanica. It was reinstated as a species following the revision of the cycads of the Andaman and Nicobar Islands published in 2020 by Lal Ji Singh and Dharm Raj Misra, of the University of Allahabad, in the Indian Journal of Forestry (volume 43, pages 46 to 57). Only the abstract of that paper could be read: it places Cycas andamanica under Cycas pschannae, Cycas darshii under Cycas sphaerica and Cycas sainathii under Cycas zeylanica, and gives a key to the species of the archipelago, but it says nothing about Cycas dharmrajii, so the arguments for its reinstatement cannot be set out here. The sources consulted do not say in which section of the genus the species belongs.

The IUCN Red List has not followed this treatment: in its assessment published in 2022, it accepts Cycas sainathii in a broad sense and includes Cycas dharmrajii, Cycas pschannae and Cycas andamanica in it as synonyms (Red List dataset relayed by GBIF, July 2026 version). The same Andaman plant may therefore be labelled under different names depending on the database consulted.

Etymology and history

The epithet honours Dharm Raj Misra, professor in the Department of Botany of the University of Allahabad, in India, for his “inspiration” and his “outstanding contribution to the knowledge of gymnosperms”, in the words of the original description as cited by The World List of Cycads.

The type was collected by Lal Ji Singh on 26 December 2013 at Table Excelsior, near Diglipur, in North Andaman, at 12 m above sea level (L.J. Singh 29600, holotype at the Central National Herbarium, Calcutta (CAL); isotype at Port Blair (PBL)). The description was reported in 2017 by the Indian press, together with that of Cycas pschannae (GKToday, 2017).

Common names

No common name is attested for this species, in English or in any language of the Andaman Islands, in the sources consulted.

In the wild

According to The World List of Cycads, Cycas dharmrajii is known only from the Andaman Islands; the type comes from the Diglipur area, in North Andaman, at low altitude. Its habitat, the extent of its populations, its pollinator and its phenology are not documented in the sources consulted, and no herbarium record of the species is published through GBIF.

Conservation status and regulation

Its status depends on the name used. For The World List of Cycads, which accepts the species, Cycas dharmrajii has not been evaluated (NE). The IUCN Red List, on the other hand, includes it in Cycas sainathii, listed as Vulnerable (VU) in L. J. Singh’s assessment published in 2022 (version 2022-1), according to the Red List dataset relayed by GBIF (checked again on 21 October 2026). The criteria and threats used could not be read, as the Red List itself could not be consulted. The 2017 original description also proposes a conservation status, but its category could not be read (paywalled article). No national protection specific to the species was found.

Like every species in the genus except Cycas beddomei, Cycas dharmrajii is listed in CITES Appendix II, through the listing of the family Cycadaceae, included since 4 February 1977. The listing carries annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen, seedlings or tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are not subject to CITES, whereas international trade in the plants themselves requires an export permit. Australia, the United Kingdom and the United States 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, does not yet list this name, published in 2017 (search of 3 October 2026): protection follows from the listing of the whole family, which covers every species, named or not. This general information does not replace the official texts: check the rules in force before buying or exchanging plants, and ask for proof that the plant was raised in cultivation.

Growing Cycas dharmrajii

In short: Cycas dharmrajii is not documented in cultivation anywhere, and nothing indicates that it is in the trade. Coming from a tropical archipelago, it would in all likelihood need tropical conditions or a heated glasshouse; this is a deduction from its origin, not documented information.

Outdoor and in-ground cultivation

No institution has published growing advice, and no grower’s report has been found on the English, French or Italian forums consulted. In theory it belongs in frost-free tropical gardens, such as those of South Florida, Hawaii or northern Australia, but no planting is documented there.

Container cultivation

In the United Kingdom and other temperate regions, a plant of this species would need a large pot in a heated glasshouse, given its giant size in the wild; again, this is a deduction, not a growing result. The Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on Cycas dharmrajii, so no Mediterranean experience can be passed on.

In cultivation in the UK, US and Australia

No record of Cycas dharmrajii was found in BGCI PlantSearch, in the online catalogues of Montgomery Botanical Center (Florida), the Royal Botanic Garden Sydney and the Australian Botanic Garden Mount Annan, or in the inventory of cycads in British, American and Australian botanic gardens compiled for this site. No report from a private grower in these countries could be read; PalmTalk and Dave’s Garden could not be consulted.

Propagation

Like all Cycas, Cycas dharmrajii is dioecious: a male and a female plant are needed for fertile seed. No germination data specific to the species have been published. Seeds are exempt from CITES under annotation #4.

Pests and diseases

One pest is documented on the species in the wild. Purti, Singh and Pandey (2022) recorded for the first time in the Andaman and Nicobar Islands the cycad blue butterfly, Luthrodes pandava, a small butterfly whose caterpillars attack all the aerial parts of cycads; they name Cycas dharmrajii and Cycas pschannae as new host plants and consider the endemic cycads of the archipelago more susceptible than introduced species. No disease specific to the species has been published. In cultivation, cycad scales, including the Asian cycad scale, Aulacaspis yasumatsui, can affect all species.

Cold hardiness

No cold-tolerance data exist for Cycas dharmrajii. It is a cycad of the Andaman Islands, in the tropics, and nothing allows us to say that it tolerates frost.

European experience

No growing result has been published in Europe, in the open ground or in a pot. Searches of the French forum Fous de palmiers and the Italian forum Tropicamente found no report for this species, and no dated frost event concerns it.

United Kingdom, United States and Australia

No planting, cold reading or growing report was found. No USDA zone can be given.

Toxicity and precautions

No toxicity analysis specific to Cycas dharmrajii has been found. The risk is, however, 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. North Carolina State University notes that cycasin is present in all parts of the plant, and the ASPCA lists the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses, with vomiting, sometimes bloody diarrhoea, jaundice and liver damage that can be fatal. Until proven otherwise, treat the plant as poisonous: wear gloves to handle the seeds and their fleshy coat, pick up fallen seeds, 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

No traditional use specific to Cycas dharmrajii has been found in the sources consulted.

Frequently asked questions

Where does Cycas dharmrajii come from?

From the Andaman Islands, in India: the type was collected near Diglipur, in North Andaman, at 12 m above sea level.

Is it a synonym of Cycas sainathii?

It depends on the source. The World List of Cycads has accepted it as a species since the 2020 revision of the archipelago’s cycads, whereas the IUCN Red List still includes it in Cycas sainathii in a broad sense.

Who is it named after?

Dharm Raj Misra, professor of botany at the University of Allahabad, in recognition of his contribution to the study of gymnosperms.

Is it endangered?

Probably. It has not been evaluated under its own name, but the Red List includes it in Cycas sainathii, listed as Vulnerable in 2022, and a pest butterfly was recorded on it in the wild in 2022.

How can it be told from Cycas pschannae?

By its trunk and its megasporophylls. According to the published descriptions, Cycas dharmrajii has a giant trunk swollen at the base and megasporophylls with many hook-shaped lateral structures, whereas Cycas pschannae has a trunk not swollen at the base and megasporophylls with two horn-shaped teeth.

Can it be grown outdoors in the UK?

No. Nothing indicates that it tolerates frost, and it is not documented in cultivation at all.

Is it poisonous?

It must be assumed so. It has not been studied, but all parts of Cycas are poisonous, especially the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Singh, L.J. (2017). Cycas dharmrajii sp. nov. (Cycadaceae) from Andaman and Nicobar Islands, India. Nordic Journal of Botany 35(1): 69–76. doi:10.1111/njb.01284 [Original description; only the abstract was consulted (Crossref), full text paywalled.]
  • Singh, L.J. & Misra, D.R. (2020). Reappraisal of the genus Cycas L. (Cycadaceae) in Andaman and Nicobar Islands, India. Indian Journal of Forestry 43(1): 46–57. doi:10.54207/bsmps1000-2021-513ETJ [Revision after which The World List of Cycads reinstated the species; only the abstract was read (Crossref), and it does not mention Cycas dharmrajii.]
  • Srivastava, R.C. & Singh, L.J. (2015). A new species of Indian Cycas. International Journal of Current Research in Biosciences and Plant Biology 2(8): 35–37. [Original description of Cycas pschannae; full text consulted.]
  • Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. [Revision of the Indian cycads; description of Cycas zeylanica used for comparison; full text consulted.]
  • Singh, L. (2022). Cycas sainathii. The IUCN Red List of Threatened Species: e.T103631608A243419871. doi:10.2305/IUCN.UK.2022-1.RLTS.T103631608A243419871.en [VU assessment of Cycas sainathii in the broad sense, including Cycas dharmrajii; reference checked on Crossref and GBIF; Red List page not consulted.]
  • Purti, N., Singh, L.J. & Pandey, A.K. (2022). New hosts for the cycad blue butterfly, Luthrodes pandava, Horsfield (Lepidoptera: Lycaenidae) in an island ecosystem. Feddes Repertorium 133(3): 234–243. doi:10.1002/fedr.202100024 [First record of the pest in the Andaman and Nicobar Islands, Cycas dharmrajii as a new host; peer-reviewed article, abstract read.]
  • Srivastava, R.C. (2014). Cycas sainathii. Indian Journal of Plant Sciences 3(1): 109–110. [Name to which the species was for a time attached; cited after The World List of Cycads, not consulted.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Source of the etymologies given 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.]