Cycas

{{Short description|Genus of cycads in the family Cycadaceae}} {{Automatic taxobox | oldest_fossil = Paleogene | image = Big Cycas.jpg | image_caption = A large cycas under development | display_parents = 2 | parent_authority = Pers.<ref name=PG1990>{{cite book |doi=10.1007/978-3-662-02604-90.0 |chapter=Cycadaceae |title=Pteridophytes and Gymnosperms |date=1990 |last1=Johnson |first1=L. A. S. |last2=Wilson |first2=K. L. |page=370 |doi-broken-date=1 July 2025 |isbn=978-3-642-08080-7 }}</ref> | taxon = Cycas | authority = L.<ref name=CycadPages>{{cite web|last=Hill|first=Ken|title=The Cycad Pages|url=https://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/cyckey.html |archive-url=https://web.archive.org/web/20210301203939/https://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/cyckey.html |archive-date=2021-03-01 |work=Genus Cycas|publisher=Royal Botanic Gardens Sydney|access-date=6 September 2013 |author2=Leonie Stanberg |author3=Dennis Stevenson}}</ref> | type_species = ''C. circinalis''<ref name=CycadPages/> | type_species_authority = L.<ref name=CycadPages/> | synonyms_ref = {{R|POWO}} | synonyms = *''Dyerocycas'' Nakai *''Epicycas'' de Laub. *''Todda-pana'' Adans. | range_map = Répartitions des Cycas.png }}

'''''Cycas''''' is a genus of cycad, and the only genus in the family '''Cycadaceae''' with all other genera of cycad being within the Zamiaceae family. ''Cycas circinalis'', a species endemic to India, was the first cycad species to be described in western literature, and is the type species of the genus.<ref>{{Cite book |last=Linnaeus |first=Carl |title=Palmae Pennatifoliae. Cycas [Cycas circinalis protologue] |year=1753 |pages=Sp. Pl. 2 : 1188}}</ref><ref>Type Location(s): LT:t. 19, in Rheede, Hort. Malab, 3 (1682)

[https://www.cycadlist.org/taxon.php?Taxon_ID=87 Cycas circinalis at The World List of Cycads] (cycadlist.org)</ref>

As of April 2024, there are 119 accepted species within the genus ''Cycas'', all of which are native to Asia, Oceania, and eastern Africa and the Indian ocean region, with the largest number of species native to Australia, China and Vietnam.<ref>119 accepted species, with 6 infraspecific taxa, as of April 21, 2024.</ref><ref name="The World List of Cycads">The World List of Cycads (WLoC), a comprehensive taxonomic reference for cycad taxonomy, nomenclature, biology, and literature. The WLoC is produced under the auspices of the [http://www.cycadgroup.org/ IUCN/SSC Cycad Specialist Group (CSG)]. The online edition is hosted and sponsored by [https://www.montgomerybotanical.org/ Montgomery Botanical Center].

Calonje M, Stevenson DW, Osborne R. The World List of Cycads, online edition [Internet]. 2013-2024. [cited 2024 Apr 21]. Available from: [http://www.cycadlist.org/ http://www.cycadlist.org].</ref><ref name="Tang-2023">{{Cite journal |last1=Donaldson, J.S. |last2=Dehgan, B. |last3=Vovides, A.P. |last4=Tang, W. |date=2003 |title=Cycads in trade and sustainable use of cycad populations |url=https://portals.iucn.org/library/efiles/documents/2003-010.pdf |journal=Cycads Status Survey and Conservation Action Plan |location=IUCN The World Conservation Union Gland, Switzerland}}</ref>

In horticulture, the most widely grown and perhaps best-known ''Cycas'' species is ''Cycas revoluta,'' which is commercially grown in large numbers for sale as houseplants or to be used in landscaping.<ref name="Tang-2023" /><ref name="cycadlist">{{Cite web |title=Cycas revoluta |url=https://cycadlist.org/taxon.php?Taxon_ID=191 |access-date=2024-04-21 |website=cycadlist.org}}</ref><ref>{{cite journal |last1=Marler |first1=Thomas E. |last2=Moore |first2=Aubrey |title=Cryptic Scale Infestations on Cycas revoluta Facilitate Scale Invasions |journal=HortScience |date=May 2010 |volume=45 |issue=5 |pages=837–839 |doi=10.21273/HORTSCI.45.5.837 |doi-access=free }}</ref>

The majority of ''Cycas'' species are highly endangered. Many are threatened by the illegal trade of wild collected plants for plant collectors, and through the conversion of land for urban development or agricultural use.<ref name="Tang-2023" />

==Range== {{See also|List of cycad species by country}} The genus ''Cycas'' is native to parts of Asia, eastern Africa and Oceania.<ref name="Tang-2023" /> ''Cycas'' has the widest distribution of any genus of cycad.<ref>Hill, K. D. (2004). Character evolution, species recognition and classification concepts in the Cycadaceae In Walters T., & Osborne R. (Eds.), ''Cycad classification, concepts and recommendations'' (pp. 23–44). Wallingford: CABI Publishing.Available as a PDF online at: [https://www.cabidigitallibrary.org/doi/pdf/10.5555/20043021917 cabidigitallibrary.org]</ref>

In Asia, ''Cycas'' (and therefore, the family Cycadaceae) represent the only cycads native to Asia. Within Asia, ''Cycas'' species are native from India and Sri Lanka in the west, through China to Japan in the north east and through south east Asia (including the Philippines) to Indonesia in the south. Globally, the northernmost species ( ''Cycas revoluta'') is found at 31°N in southern Japan.<ref name="Tang-2023" /><ref name="cycadlist" />

As of April 2024, the largest number of currently accepted species of ''Cycas'' in Asia are found in Vietnam (27 species), China (23 species), India (14 species), Thailand (12 species), Philippines (12 species) and Indonesia (10 species).<ref name="The World List of Cycads" /> The distribution of Cycas species in Myanmar, Laos, and Cambodia is not well known, but as of April 2024, no accepted cycad species is known to be endemic to any of these three countries.<ref name="The World List of Cycads" /><ref name="Tang-2023" />

In Africa, cycads belonging to all three cycad families are found making it a major center of diversity for cycads in general, but only one ''Cycas'' species (''Cycas thouarsii)'' is native and it is restricted to eastern Africa and nearby island nations. ''C. thouarsii'' grows in a comparatively wide area including coastal regions of Mozambique, Tanzania, and Kenya in mainland Africa, extending to the Seychelles, Madagascar and Comoros islands in the Indian Ocean.<ref name="Tang-2023" /><ref>{{Cite web |title=Cycas thouarsii |url=https://cycadlist.org/taxon.php?Taxon_ID=228 |access-date=2024-04-21 |website=cycadlist.org}}</ref>

In Oceania, ''Cycas'' species are native to Australia, Papua New Guinea, and the island nations of the Pacific Ocean region, but are absent from New Zealand. As in Asia, ''Cycas'' is the only genus of cycad found across the region, with the exception for Australia, where cycads native to all three families of cycads are found. Despite this, Australia also has the largest number of ''Cycas'' species globally with 34 native ''Cycas'' species accepted (as of April 2024), including the southernmost species globally (''Cycas megacarpa'') found at 26°S in southeast Queensland.<ref name="The World List of Cycads" /><ref name="Tang-2023" /><ref>{{Cite web |title=Cycas megacarpa |url=https://cycadlist.org/taxon.php?Taxon_ID=162 |access-date=2024-04-21 |website=cycadlist.org}}</ref> At least 7 ''Cycas'' species are found in Papua New Guinea, some of which are also found in parts of neighbouring Indonesia.<ref name="The World List of Cycads" /> In the broader region, ''Cycas seemannii'' is found in Melanesia and western Polynesia and ''Cycas micronesica'' is found across Micronesia.<ref name="Tang-2023" /><ref>{{Cite web |title=Cycas seemannii |url=https://cycadlist.org/taxon.php?Taxon_ID=206 |access-date=2024-04-21 |website=cycadlist.org}}</ref><ref>{{Cite web |title=Cycas micronesica |url=https://cycadlist.org/taxon.php?Taxon_ID=165 |access-date=2024-04-21 |website=cycadlist.org}}</ref>

Globally, some ''Cycas'' species are considered to be relatively widespread, for example ''Cycas thouarsii'' is native to a large area of mainland Africa and islands of the Indian Ocean, and ''Cycas pectinata'' and ''Cycas clivicola'' are both native to large areas of Asia; however, most ''Cycas'' species have restricted distributions, with some restricted to very small areas. In Asia, for example, more than 75% of species occur in no more than one country. For some countries, even though the number of species may not be high, the level of species-specific genetic variation can be very high meaning that so that even countries with few species, it may contain distinct gene pools of widespread species.<ref name="Tang-2023" /><ref>{{cite journal |last1=Xiao |first1=Siyue |last2=Ji |first2=Yunheng |last3=Liu |first3=Jian |last4=Gong |first4=Xun |title=Genetic characterization of the entire range of Cycas panzhihuaensis (Cycadaceae) |journal=Plant Diversity |date=February 2020 |volume=42 |issue=1 |pages=7–18 |doi=10.1016/j.pld.2019.10.001 |pmid=32140633 |pmc=7046506 |bibcode=2020PlDiv..42....7X }}</ref>

==Evolution== thumb|upright|left|''Cycas'' sp. ''Cycas'' (and the Cycadaceae family) is considered as being an early offshoot that diverged early from all other living cycads (which belong to the family Zamiaceae). Estimates of the timing of the split ranging from the Jurassic<ref>{{cite journal |last1=Nagalingum |first1=N. S. |last2=Marshall |first2=C. R. |last3=Quental |first3=T. B. |last4=Rai |first4=H. S. |last5=Little |first5=D. P. |last6=Mathews |first6=S. |title=Recent Synchronous Radiation of a Living Fossil |journal=Science |date=11 November 2011 |volume=334 |issue=6057 |pages=796–799 |doi=10.1126/science.1209926 |pmid=22021670 |bibcode=2011Sci...334..796N |s2cid=206535984 }}</ref> to the Carboniferous.<ref name="Coiro-2023" /> The earliest fossils assignable to ''Cycas'' are known from the Paleogene of East Asia, such as ''Cycas fushunensis'' from the Eocene (around 47.5 million years ago) of Northeast China with East Asia likely representing the ancestral homeland of the genus.<ref>{{cite journal |last1=Liu |first1=Jian |last2=Lindstrom |first2=Anders J |last3=Marler |first3=Thomas E |last4=Gong |first4=Xun |date=28 January 2022 |title=Not that young: combining plastid phylogenomic, plate tectonic and fossil evidence indicates a Palaeogene diversification of Cycadaceae |journal=Annals of Botany |volume=129 |issue=2 |pages=217–230 |doi=10.1093/aob/mcab118 |pmc=8796677 |pmid=34520529}}</ref> The presence of ''Cycas'' in Australasia and eastern Africa is relatively new, but the major evolutionary events behind the genesis of new species have taken place in Indochina and Australia, where the majority of living species are native.<ref name="Tang-2023" />

Fossil seeds from the Middle Jurassic of England and British Columbia were suggested in a 2017 study to be more closely related to ''Cycas'' than other cycads and were assigned to the same family, Cycadaceae'''.<ref>{{Cite journal |last1=Spencer |first1=Alan R. T. |last2=Garwood |first2=Russell J. |last3=Rees |first3=Andrew R. |last4=Raine |first4=Robert J. |last5=Rothwell |first5=Gar W. |last6=Hollingworth |first6=Neville T. J. |last7=Hilton |first7=Jason |date=2017-08-28 |title=New insights into Mesozoic cycad evolution: an exploration of anatomically preserved Cycadaceae seeds from the Jurassic Oxford Clay biota |journal=PeerJ |language=en |volume=5 |article-number=e3723 |doi=10.7717/peerj.3723 |issn=2167-8359 |pmc=5578371 |pmid=28875075 |doi-access=free }}</ref>''' A later study suggested that these seeds could not be assigned to the stem-group of ''Cycas'' with confidence due to lacking the double vascular system that characterises the seeds of all living cycads.<ref>{{cite journal |last1=Rothwell |first1=Gar W. |last2=Stockey |first2=Ruth A. |last3=Stevenson |first3=Dennis W. |last4=Zumajo-Cardona |first4=Cecilia |title=Large Permineralized Seeds in the Jurassic of Haida Gwaii, Western Canada: Exploring the Mode and Tempo of Cycad Evolution |journal=International Journal of Plant Sciences |date=October 2022 |volume=183 |issue=8 |pages=674–690 |doi=10.1086/721710 |bibcode=2022IJPlS.183..674R |hdl=2434/975729 |hdl-access=free }}</ref> The leaf fossil genus ''Paracycas'' known from the Jurassic and Cretaceous of Europe has been suggested to be early representatives of the ''Cycas'' lineage by cladistic analysis.<ref name="Coiro-2023">{{Cite journal |last1=Coiro |first1=Mario |last2=Allio |first2=Rémi |last3=Mazet |first3=Nathan |last4=Seyfullah |first4=Leyla J. |last5=Condamine |first5=Fabien L. |date=2023-06-11 |title=Reconciling fossils with phylogenies reveals the origin and macroevolutionary processes explaining the global cycad biodiversity |journal=New Phytologist |volume=240 |issue=4 |pages=1616–1635 |language=en |doi=10.1111/nph.19010 |pmid=37302411 |pmc=10953041 |bibcode=2023NewPh.240.1616C |s2cid=259137975 |issn=0028-646X}}</ref> thumb|upright|left|Bark of ''Cycas rumphii''

[[Image:Cycas male cone.jpg|thumb|upright|right|A male cone of ''Cycas circinalis'']] {{Multiple image |title = ''Cycas'' native to Odisha |image1 = Cycas nayagarhensis Singh Radha Khuraijam.JPG |image2 = Cycas orixensis Singh Khuraijam.JPG |caption1 = ''Cycas nayagarhensis'' male cone |caption2 = ''Cycas orixensis'' male cone }}

==Conservation status== ''Cycas'' species are threatened worldwide and almost all the species are listed in the IUCN Red List. ''Cycas beddomei'' is the only species of the genus ''Cycas'' listed in Appendix I of CITES. All other members of ''Cycadaceae'' are listed under Appendix II.<ref>{{cite web|url=https://cites.org/eng/app/appendices.php|title=Appendices I, II and III|website=Convention on International Trade in Endangered Species of Wild Fauna and Flora|date=21 May 2023|access-date=22 August 2023}}</ref> ''Cycas rumphii'' and ''Cycas pectinata'' have the most widespread distribution.{{cn|date=February 2025}}

==Phylogeny== [[File:Cycas media megasporophylls.jpg|thumb|''Cycas media'' megasporophylls with nearly-mature seeds on a wild plant in north Queensland, Australia]] [[File:Cycas media.JPG|thumb|Grove of ''Cycas media'' in north Queensland]] [[File:Cycas platyphylla with new flush of fronds.JPG|thumb|''Cycas platyphylla'' in north Queensland with new flush of fronds during the rainy season, still with glaucous bloom]] {| class="wikitable" |- ! colspan=1 |Phylogeny of ''Cycas''<ref>{{cite journal |last1=Stull |first1=Gregory W. |last2=Qu |first2=Xiao-Jian |last3=Parins-Fukuchi |first3=Caroline |last4=Yang |first4=Ying-Ying |last5=Yang |first5=Jun-Bo |last6=Yang |first6=Zhi-Yun |last7=Hu |first7=Yi |last8=Ma |first8=Hong |last9=Soltis |first9=Pamela S. |last10=Soltis |first10=Douglas E. |last11=Li |first11=De-Zhu |last12=Smith |first12=Stephen A. |last13=Yi |first13=Ting-Shuang |title=Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms |journal=Nature Plants |date=19 July 2021 |volume=7 |issue=8 |pages=1015–1025 |doi=10.1038/s41477-021-00964-4 |pmid=34282286 |bibcode=2021NatPl...7.1015S }}</ref> |- | style="vertical-align:top| {{clade|style=font-size:90%;line-height:80% |1={{clade |1={{clade |label1=section |sublabel1=''Stangerioides'' |1=''C. micholitzii'' Dyer }} |2={{clade |1={{clade |label1=(''Pectinata'') |1={{clade |1=''C. multipinnata'' C.J.Chen & S.Y.Yang |2=''C. pectinata'' Buch.-Ham. }} }} |2={{clade |1=''C. thouarsii'' R.Br. ex Gaudichaud-Beaupré |2={{clade |label1=(''Panzhihuaenses'') |1={{clade |label1=section |sublabel1=''Asiorientales'' |1={{clade |1=''C. revoluta'' Thunb. (Sago palm) |2=''C. taitungensis'' Shen et al. }} |label2=section |sublabel2=''Panzhihuaenses'' |2={{clade |1=''C. tropophylla'' K.D.Hill & P.K.Lôc |2={{clade |1=''C. ferruginea'' F.N.Wei |2={{clade |1=''C. curranii'' (J.Schust.) K.D.Hill |2={{clade |1=''C. debaoensis'' Y.C.Zhong & C.J.Chen |2={{clade |1=''C. brachycantha'' K.D.Hill, H.T.Nguyen & P.K.Lôc |2=''C. immersa'' Craib }} }} }} }} }} }} |label2=(''Cycas'') |2={{clade |1=''C. bifida'' (Dyer) K.D.Hill |2={{clade |1=''C. szechuanensis'' W.C.Cheng & L.K.Fu |2={{clade |1={{clade |label1=section |sublabel1=''Wadeanae'' |1={{clade |label1=subsection |sublabel1=''Wadeanae'' |1=''C. wadei'' Merr. |label2=subsection |sublabel2=''Taiwanianosae'' |2={{clade |1=''C. hainanensis'' C.J.Chen |2={{clade |1=''C. taiwaniana'' Carruthers |2=''C. fairylakea'' D.Y.Wang }} }} }} }} |2={{clade |label1=section |sublabel1=''Cycas'' |1={{clade |label1=subsection |sublabel1=''Cycas'' |1={{clade |1=''C. circinalis'' L. (Indu) |2=''C. micronesica'' K.D.Hill }} |label2=subsection |sublabel2=''Rumphiae'' |2={{clade |1=''C. pschannae'' R.C.Srivast. & L.J.Singh |2={{clade |1=''C. edentata'' de Laub. |2={{clade |1=''C. nitida'' K.D.Hill & A.Lindstr. |2=''C. rumphii'' Miq. }} }} }} }} |2={{clade |label1=section |sublabel1=''Indosinenses'' |1={{clade |1=''C. clivicola'' K.D.Hill |2={{clade |label1=subsection |sublabel1=''Indosinenses'' |1={{clade |1=''C. siamensis'' Miq. |2={{clade |1=''C. vespertilio'' A.Lindstr. & K.D.Hill |2={{clade |1=''C. riuminiana'' M.Porte ex Regel |2={{clade |1=''C. bougainvilleana'' K.D.Hill |2=''C. celebica'' Miq. }} }} }} }} |label2=subsection |sublabel2=''Lindstroemiae'' |2={{clade |1=''C. macrocarpa'' Griff. |2={{clade |1=''C. nongnoochiae'' K.D.Hill |2={{clade |1=''C. elongata'' (Leandri) D.Y.Wang |2={{clade |1=''C. tansachana'' K.D.Hill & S.L.Yang |2={{clade |1=''C. lindstromii'' S.L.Yang, K.D.Hill & Nguyên |2={{clade |1=''C. condaoensis'' K.D.Hill & S.L.Yang |2={{clade |1=''C. chamaoensis'' K.D.Hill |2=''C. media'' R.Br. }} }} }} }} }} }} }} }} }} |label2=section |sublabel2=''Endemicae'' |2={{clade |1=''C. diannanensis'' Z.T.Guan & G.D.Tao |2={{clade |1=''C. cairnsiana'' F.Muell. |2={{clade |1=''C. petrae'' A.Lindstr. & K.D.Hill |2={{clade |1=''C. megacarpa'' K.D.Hill |2={{clade |1=''C. calcicola'' Maconochie |2={{clade |1=''C. armstrongii'' Miq. |2={{clade |1=''C. balansae'' Warb. |2={{clade |1=''C. segmentifida'' D.Y.Wang & C.Y.Deng |2={{clade |1=''C. dolichophylla'' K.D.Hill, H.T.Nguyen & P.K.Lôc |2={{clade |1=''C. simplicipinna'' (Smitinand) K.D.Hill |2={{clade |1=''C. guizhouensis'' K.M.Lan & R.F.Zou |2={{clade |1=''C. chevalieri'' Leandri |2={{clade |1=''C. maconochiei'' Chirgwin & K.D.Hill |2={{clade |1=''C. arenicola'' K.D.Hill |2={{clade |1={{clade |1=''C. schumanniana'' Lauterb. |2={{clade |1=''C. aculeata'' K.D.Hill & H.T.Nguyen |2=''C. silvestris'' K.D.Hill }} }} |2={{clade |1=''C. basaltica'' C.A.Gardner |2={{clade |1=''C. semota'' K.D.Hill |2={{clade |1=''C. orientis'' K.D.Hill |2={{clade |1=''C. canalis'' K.D.Hill |2={{clade |1=''C. hongheensis'' S.Y.Yang & S.L.Yang |2={{clade |1=''C. conferta'' Chirgwin |2={{clade |1=''C. angulata'' R.Br. |2={{clade |1={{clade |1=''C. couttsiana'' K.D.Hill |2={{clade |1=''C. ophiolitica'' K.D.Hill |2={{clade |1=''C. tanqingii'' D.Y.Wang |2=''C. platyphylla'' K.D.Hill }} }} }} |2={{clade |1=''C. indica'' A.Lindstr. & K.D.Hill (=''Cycas swamyi'') |2={{clade |1=''C. annaikalensis'' Rita Singh & P.Radha |2={{clade |1=''C. beddomei'' Dyer |2=''C. sphaerica'' Roxb. }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} }} |}

Other species: {{div col|colwidth=18em}} *''Cycas aenigma'' K.D.Hill & A.Lindstr. *''Cycas apoa'' K.D.Hill *''Cycas arnhemica'' K.D.Hill *''Cycas badensis'' K.D.Hill *''Cycas bglswamyi'' Pant ex Agrawal, Akhtar & R.C.Srivast. *''Cycas brunnea'' K.D.Hill *''Cycas campestris'' K.D.Hill *''Cycas candida'' K.D.Hill *''Cycas cantafolia'' Jutta, K.L.Chew & Saw *''Cycas changjiangensis'' N.Liu *''Cycas chenii'' X.Gong & Wei Zhou *''Cycas collina'' K.D.Hill, H.T.Nguyen & P.K.Lôc *''Cycas cupida'' P.I.Forst. *''Cycas darshii'' R.C.Srivast. & Jana *''Cycas desolata'' P.I.Forst. *''Cycas dharmrajii'' L.J.Singh *''Cycas distans'' P.I.Forst. & B.Gray *''Cycas divyadarshanii'' Khuraijam & Rita Singh *''Cycas elephantipes'' A.Lindstr. & K.D.Hill *''Cycas falcata'' K.D.Hill *''Cycas flabellata'' Agoo, Madulid & J.R.Callado *''Cycas fugax'' K.D.Hill, H.T.Nguyen & P.K.Lôc *''Cycas furfuracea'' W.Fitzg. *''Cycas glauca'' Miq. *''Cycas hoabinhensis'' Lôc & H.T.Nguyen *''Cycas inermis'' Oudem. *''Cycas javana'' (Miq.) de Laub. *''Cycas lacrimans'' A.Lindstr. & K.D.Hill *''Cycas lane-poolei'' C.A.Gardner *''Cycas laotica'' T.H.Nguyên & K.S.Nguyen *''Cycas litoralis'' K.D.Hill *''Cycas mindanaensis'' Agoo, Madulid & J.R.Callado *''Cycas miquelii'' Warb. *''Cycas montana'' A.Lindstr. & K.D.Hill *''Cycas nayagarhensis'' Rita Singh, P.Radha & Khuraijam *''Cycas nathorstii'' J.Schust. *''Cycas orixensis'' (Haines) Rita Singh & Khuraijam *''Cycas pachypoda'' K.D.Hill *''Cycas panzhihuaensis'' Zhou & S.Y.Yang *''Cycas papuana'' F.Muell. *''Cycas pectinata'' *''Cycas pranburiensis'' S.L.Yang et al. *''Cycas pruinosa'' Maconochie *''Cycas sainathii'' R.C.Srivast. *''Cycas sancti-lasallei'' Agoo & Madulid *''Cycas saxatilis'' K.D.Hill & A.Lindstr. *''Cycas scratchleyana'' F.Muell. *''Cycas seemannii'' A.Braun *''Cycas seshachalamensis'' P.V.C.Rao et al. *''Cycas sexseminifera'' F.N.Wei *''Cycas shanyaensis'' Fu *''Cycas sundaica'' Miq. ex A.Lindstr. & K.D.Hill *''Cycas terryana'' P.I.Forst. *''Cycas tuckeri'' K.D.Hill *''Cycas xipholepis'' K.D.Hill *''Cycas yorkiana'' K.D.Hill *''Cycas yunnanensis'' Cheng, Fu & Cheng *''Cycas zambalensis'' Madulid & Agoo *''Cycas zeylanica'' (J.Schust.) A.Lindstr. & K.D.Hill {{div col end}}

==References== {{Reflist|refs= <ref name="POWO">{{cite web |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:326847-2 |title=''Cycas'' L. |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=28 March 2023}}</ref> }}

==External links== *{{cite journal | last1 = de Laubenfels | first1 = D.J. | last2 = Adema | first2 = F. | year = 1998 | title = A taxonomic revision of the genera ''Cycas'' and ''Epicycas'' Gen. Nov. (Cycadaceae) | url =http://www.repository.naturalis.nl/document/565822 | journal = Blumea | volume = 43 | pages = 351–400 }} *Hill, K.D.(1998–2004) The Cycad Pages, Royal Botanic Gardens Sydney. http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/index.html {{Webarchive|url=https://web.archive.org/web/20210329132148/https://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/index.html |date=2021-03-29 }} *[https://web.archive.org/web/20080403033422/http://www.plantapalm.com/vce/vce_index.htm Virtual Cycad Encyclopedia] edited by the Palm & Cycad Societies of Florida *David, J. de Laubenfels, [https://web.archive.org/web/20090213143743/http://delaubenfels.com/content/blogcategory/18/78/ Cycas Taxonomy] *{{cite journal | last1 = Hill | first1 = K.D. | last2 = Stevenson | first2 = Dennis W. | last3 = Osborne | first3 = Roy | year = 2004 | title = The World List of Cycads | journal = The Botanical Review | volume = 70 | issue = 2| pages = 274–298 | doi = 10.1663/0006-8101(2004)070[0274:TWLOC]2.0.CO;2 | s2cid = 36921733 }} *{{cite journal | last1 = Lindstrom | first1 = Anders J. | last2 = Hill | first2 = Ken D. | year = 2007 | title = The genus ''Cycas'' (Cycadaceae) in India | url = http://plantnet.rbgsyd.nsw.gov.au/emuwebnswlive/objects/common/webmedia.php?irn=46748&reftable=ebibliography | journal = Telopea | volume = 11 | issue = 4| pages = 463–488 | doi=10.7751/telopea20075745| bibcode = 2007Telop..11..463L | doi-access = free }} *Singh, R & JS Khuraijam (2013-) Cycads of India. http://www.cycadsofindia.in/ {{Webarchive|url=https://web.archive.org/web/20210118092551/http://www.cycadsofindia.in/ |date=2021-01-18 }} *{{cite journal | last1 = Singh | first1 = R. | last2 = Radha | first2 = P. | last3 = Khuraijam | first3 = J.S. | year = 2015 | title = A new species, a new combination and a new subsection of Cycas from Odisha, northern Eastern Ghats of India | journal = Asian Journal of Conservation Biology | volume = 4 | issue = 1| pages = 3–14 }} *{{cite journal | last1 = Singh | first1 = R. | last2 = Radha | first2 = P. | year = 2006 | title = ''Cycas annaikalensis'', A new species of ''Cycas'' from the Malabar Coast, Western Ghats, India | journal = Brittonia | volume = 58 | issue = 2| pages = 119–123 | doi=10.1663/0007-196x(2006)58[119:ansocf]2.0.co;2| s2cid = 32241023 }} *Terrence Walters & Roy Osborne (eds.) (2004), ''Cycad Classification: Concepts and Recommendations'', CABI publishing, {{ISBN|0-85199-741-4}}

Category:Cycas Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus Category:Gymnosperm genera {{Improve categories|date=February 2025}}