Ophioglossum petiolatumHook.

adder's tonguelongstem adderstongue

WFO wfo-0001109041 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Ophioglossum petiolatum, photographed by Jacy Chen
fig. a Jacy Chen, CC BY 4.0 / 2022-01-23 / obs. 177014823

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
02361499
Filed as
Ophioglossum petiolatum Hook.
Det. by
R. D. Thomas 1974-01-01
Collected
E. P. St. John 1934
Origin
US
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 51 botanical countries

Regions where Ophioglossum petiolatum is native: China South-Central, China Southeast, Hainan, Japan, Nansei-shoto, Ogasawara-shoto, Taiwan, Tibet, Assam, Bangladesh, Bismarck Archipelago, Borneo, Christmas I., East Himalaya, India, Jawa, Lesser Sunda Is., Malaya, Maluku, Myanmar, Nepal, New Guinea, Pakistan, Philippines, Solomon Is., Sri Lanka, Sumatera, Thailand, Vietnam, West Himalaya, Chatham Is., Kermadec Is., New South Wales, New Zealand North, New Zealand South, Norfolk Is., Northern Territory, Queensland, Victoria, Western Australia, Mexico Southeast, Mexico Southwest, Caroline Is., Fiji, Hawaii, New Caledonia, Niue, Samoa, Society Is., Tubuai Is., Vanuatu China South-CentralChina SoutheastHainanJapanTaiwanTibetAssamBangladeshBismarck ArchipelagoBorneoEast HimalayaIndiaJawaLesser Sunda Is.MalayaMalukuMyanmarNepalNew GuineaPakistanPhilippinesSolomon Is.Sri LankaSumateraThailandVietnamWest HimalayaNew South WalesNew Zealand NorthNew Zealand SouthNorthern TerritoryQueenslandVictoriaWestern AustraliaMexico SoutheastMexico SouthwestFijiHawaiiNew Caledonia Nansei-shotoChristmas I.Chatham Is.Kermadec Is.Norfolk Is.Caroline Is.NiueSamoaSociety Is.Tubuai Is.Vanuatu
Native distribution of Ophioglossum petiolatum, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Assam ASS ASIA-TROPICAL
Bangladesh BAN
Bismarck Archipelago BIS
Borneo BOR
Christmas I. XMS
East Himalaya EHM
India IND
Jawa JAW
Lesser Sunda Is. LSI
Malaya MLY
Maluku MOL
Myanmar MYA
Nepal NEP
New Guinea NWG
Pakistan PAK
Philippines PHI
Solomon Is. SOL
Sri Lanka SRL
Sumatera SUM
Thailand THA
Vietnam VIE
West Himalaya WHM
Chatham Is. CTM AUSTRALASIA
Kermadec Is. KER
New South Wales NSW
New Zealand North NZN
New Zealand South NZS
Norfolk Is. NFK
Northern Territory NTA
Queensland QLD
Victoria VIC
Western Australia WAU
Caroline Is. CRL PACIFIC
Fiji FIJ
Hawaii HAW
New Caledonia NWC
Niue NUE
Samoa SAM
Society Is. SCI
Tubuai Is. TUB
Vanuatu VAN
China South-Central CHC ASIA-TEMPERATE
China Southeast CHS
Hainan CHH
Japan JAP
Nansei-shoto NNS
Ogasawara-shoto OGA
Taiwan TAI
Tibet CHT
Mexico Southeast MXT NORTHERN AMERICA
Mexico Southwest MXS

Not drawn on the map: Ogasawara-shoto. We hold no public-domain boundary for this region, so it is listed rather than guessed at.

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 382 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 1.4 °C 12.4 °C 16.4 °C
Warmest month, mean daily high 21.9 °C 30.4 °C 32.0 °C
Annual rainfall 1,285 mm 2,594 mm 4,103 mm
Rainfall in the driest quarter 59 mm 263 mm 676 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 382 research-grade observations of Ophioglossum petiolatum that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 12 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Ophioglossum cognatum C.Presl
  • Ophioglossum elongatum A.Cunn.
  • Ophioglossum floridanum E.P.St.John
  • Ophioglossum floridanum f. favosum E.P.St.John
  • Ophioglossum floridanum f. reticulosum E.P.St.John
  • Ophioglossum litorale Makino
  • Ophioglossum littorale Makino
  • Ophioglossum moluccanum Schltdl.
  • Ophioglossum moluccanum f. complicatum Miq.
  • Ophioglossum pedunculosum var. australasiaticum (Luerss.) C.Chr.
  • Ophioglossum reticulatum f. complicatum (Miq.) Wieff.
  • Ophioglossum vulgatum var. australasiaticum Luerss.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.