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This species is accepted, and its native range is Myanmar to N. Thailand.
A specimen from Kew's Herbarium


Suddee, S., A. J. Paton, & Parnell, J. (2004). A Taxonomic Revision of Tribe Ocimeae Dumort. (Lamiaceae) in Continental South East Asia II. Plectranthinae. Kew Bulletin, 59(3), 379-414. doi:10.2307/4110950

Known from three localities and with an estimated extent of occurrence of less than 200 km2. The Thai locality is in the middle of an agricultural area and thus prone to disturbance. This population was very small and restricted to an area of around 20 m2. Nothing is known about the Burmese localities. EN B1+2 ab(i,ii,iii).
Burma & Thailand.
In wet areas, open places along trails by waterfalls on limestone; 600 m.
Morphology General Habit
Erect annual or short-lived perennial herbs up to 1 m tall
Morphology Leaves
Leaves thin, lanceolate or ovate-lanceolate, 30 - 100 x 15 - 30 mm, apex acute, base cuneate or attenuate and decurrent on petiole, margin serrate- crenate above, entire near base, puberulous on both sides, sessile glands prominent beneath, veins prominent beneath; petioles 5 - 15 mm long, puberulous
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens united for nearly half of their length, posterior pair subequal to anterior corolla lip, anterior pair slightly exceeding it
Morphology Reproductive morphology Flowers Calyx
Calyx tubular, 2 - 3 mm long at anthesis, 6 - 7 mm long in fruit; posterior lip orbicular, margin irregularly denticulate, decurrent on tube, glabrous inside, sparsely pubescent with simple and gland-tipped hairs outside, nerves prominent both sides; anterior lip with median teeth lanceolate, slightly shorter than posterior lip, lateral teeth obovate- oblong, irregularly denticulate at apex, ± the same length as median teeth; tube 10-nerved, slightly constricted at throat, densely hirsute with short and long simple and gland-tipped patent hairs, with pointed spur at anterior base
Morphology Reproductive morphology Flowers Corolla
Corolla purple, 10 - 11 mm long; posterior lip with minute lobes, obtuse at apex, glabrous on back, lateral lobes slightly broader than median lobes but equal in length; anterior lip obovate, 3- 4 mm long, flattened, apex pubescent outside, villous inside; tube 6- 7 mm long, sigmoid below the middle, slender below, gradually dilated towards throat, slightly pubescent on anterior side outside, otherwise glabrous
Morphology Reproductive morphology Flowers Disc
Disc with anterior side thick, obtuse at apex, twice as long as ovary
Morphology Reproductive morphology Flowers Gynoecium Style
Style shortly bifid with subequal branches, ± the same length as posterior stamens
Morphology Reproductive morphology Fruits
Nutlets black, ellipsoid, c. 1 mm long, minutely tuberculate, producing mucilage when wet.
Morphology Reproductive morphology Inflorescences
Inflorescence terminal, up to 20 cm long, often with several lateral long branches; axis densely hirsute with simple and gland-tipped patent hairs and with sessile glands; verticils 5 - 10 mm apart, slightly interrupted; cymes sessile, 2 - 3-flowered; bracts sessile or with short claw at base, caducous, ovate, 4 - 6 mm long, acute, ciliate, pubescent; pedicels 0.5 - 1 mm long at anthesis, 2 - 2.5 mm long in fruit, pubescent with short patent hairs
Morphology Stem
Stems sometimes purple, quadrangular or round- quadrangular, branched, glabrous below, pubescent above
Prain (1897) mentioned in his original publication of Plectranthus fulvescens that the filaments were free from each other from their point of insertion on the corolla tube. In Thai specimens, however, the staminal filaments are united for a considerable distance above this point. There is no flower left on the isotype of P. fulvescens at Kew and the holotype of P. helferi is a fruiting specimen. Because of the lack of flowering material for the original description, Hooker (1885) published the name of the species as P? helferi as there was no flower available for his original description. However, the Thai specimens and the isotype of P. fulvescens are identical with the holotype of P. helferi in all other characters.
Flowering & fruiting October - December.
Burma, Tenasserim, Helfer 4061 (holotype K!).

Native to:

Myanmar, Thailand

Coleus helferi (Hook.f.) A.J.Paton appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 1999 Helfer, J.W. [4061], Burma Plectranthus helferi K000820173 holotype
Apr 3, 2000 Brandis, D. [s.n.] Plectranthus fulvescens K000820172 isotype

First published in PhytoKeys 129: 56 (2019)

Accepted by

  • Govaerts, R., Nic Lughadha, E., Black, N., Turner, R. & Paton, A. (2021). The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8: 215.

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Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at and
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.