Mitragyna inermis(Willd.) Kuntze

WFO wfo-0000244931 Accepted WFO 2026-06 3 photographs CC BY

Plate 1 figs. a–c · 1 observation

This species has been photographed under an open licence only 1 time, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.

Mitragyna inermis, photographed by Sunday Berlioz KAKPO
fig. a Sunday Berlioz KAKPO, CC BY 4.0 / 2019-03-27 / obs. 33676872

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
Royal Botanic Gardens, Kew
Accession
K000394922
Filed as
Mitragyna inermis (Willd.) Kuntze
Det. by
Hutchinson; Dalziel
Collected
Vogel
Origin
NG
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. We link to the digitised sheet rather than rehosting it, because the holding institutions do not serve their images to third parties reliably and we are not going to show you a picture we cannot actually deliver. 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 sheets never recorded a determiner, which is ordinary.

Native range 20 botanical countries

Regions where Mitragyna inermis is native: Benin, Burkina, Cameroon, Central African Republic, Chad, DR Congo, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, Sudan-South Sudan, Togo BeninBurkinaCameroonCentral African RepublicChadDR CongoGambiaGhanaGuineaGuinea-BissauIvory CoastLiberiaMaliMauritaniaNigerNigeriaSenegalSierra LeoneSudan-South SudanTogo
Native distribution of Mitragyna inermis, 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.
RegionTDWG codeContinent
Benin BEN AFRICA
Burkina BKN
Cameroon CMN
Central African Republic CAF
Chad CHA
DR Congo ZAI
Gambia GAM
Ghana GHA
Guinea GUI
Guinea-Bissau GNB
Ivory Coast IVO
Liberia LBR
Mali MLI
Mauritania MTN
Niger NGR
Nigeria NGA
Senegal SEN
Sierra Leone SIE
Sudan-South Sudan SUD
Togo TOG

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 135 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 14.2 °C 19.1 °C 20.4 °C
Warmest month, mean daily high 33.0 °C 39.2 °C 40.8 °C
Annual rainfall 591 mm 956 mm 1,238 mm
Rainfall in the driest quarter 0 mm 1 mm 15 mm

It is not found anywhere that gets close to freezing. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 135 research-grade observations of Mitragyna inermis 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 9 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.

  • Adina inermis (Willd.) Roberty
  • Cephalanthus africanus Rchb. ex DC.
  • Mitragyna africana (Willd.) Korth.
  • Nauclea africana Willd.
  • Nauclea inermis (Willd.) Baill.
  • Nauclea platanocarpa Hook.f.
  • Platanocarpum africanum (Willd.) Hook.f.
  • Stephegyne africana (Willd.) Walp.
  • Uncaria inermis Willd.

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. 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.