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This species is accepted, and its native range is Tanzania to S. Tropical Africa.
A specimen from Kew's Herbarium


Lamiaceae (Labiatae), A.J. Paton, G. Bramley, O. Ryding, R.M. Polhill, Y.B. Harvey, M. Iwarsson, F. Willis, P.B. Phillipson, K. Balkwill, C.W. Lukhoba, D.F. Otieno, & R.M. Harley. Pycnostachys, G Bramleyshaped. Flora of Tropical East Africa. 2009

Type: Mozambique, Gorongoza, near Gouveia, Carvalho s.n. (B†, holo. COI!, iso., K!, fragment)
Morphology General Habit
Annual or short-lived perennial herb, 0.5–1 m tall, apex herbaceous
Morphology Stem
Stems erect, branching, quadrangular, pubescent with short eglandular hairs and red sessile glands
Morphology Leaves
Leaves opposite, petiolate; blades broadly to narrowly ovate 4–13.5 × 2.5–8.5 cm, serrate, apex acuminate, base shortly attenuate down petiole, also with red or yellow sessile glands beneath and pubescent with short, stiff eglandular hairs, the hairs more plentiful on margins and venation; petiole 10–55 mm long
Morphology Reproductive morphology Inflorescences
Inflorescence usually dense, occasionally more lax in fruit so axis visible, when in flower forming a narrow conical shape, in fruit expanding to 50–145 × 15–22 mm; flowers sessile in single flowered cymes; bracts subtending entire inflorescence ovate, 15–50 mm long, apex acute, enclosing buds then becoming deflexed in flower, pubescent with short eglandular hairs, persistent through flowering stage; bracts subtending single flowers linear to lanceolate, 3–4 mm long, ciliate
Morphology Reproductive morphology Flowers Calyx
Calyx with tube ± 1 mm long at anthesis, outer surface with eglandular and glandular hairs and yellow and red sessile glands, sometimes the red sessile glands dense on the ventral surface of the tube, inner surface with 0.5 mm long triangular scales present between calyx lobes, below these a fringe of eglandular hairs which lengthen in fruit; lobes 5, subulate, ± subequal, 2–4 mm long; fruiting calyx with tube 3–4.5 mm long, ventrally gibbous, lobes ± straight, lengthening to 3–7 mm
Morphology Reproductive morphology Flowers Corolla
Corolla pale blue or lavender, 11–17 mm long; tube very narrow and parallel-sided for 4–8 mm, then curving sharply downwards and broadening for ± 3 mm before opening into two lips; posterior lip much shorter than anterior, 1–2 mm long, backs of lobes with scattered eglandular hairs and yellow sessile glands; anterior lip 4–8 mm long, 2–4.5 mm deep, with scattered hairs and yellow sessile glands on the front of lip
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens connate for ± 2 mm, exserted for ± 1 mm
Morphology Reproductive morphology Fruits
Nutlets ± 1 mm long.
Dry or seasonally wet open woodland, bushland or thicket, waste ground, on clayey or sandy loam, or sand; 500–1500 m
Least Concern: widely distributed in several countries and liable to be favoured by disturbance.
Pycnostachys orthodonta is a widely distributed, apparently annual herb, variable in the indumentum of the calyx, but its distinctive delicate, long-petiolate, ovate leaves with shortly attenuate bases remain constant throughout its distribution. It can be informally divided into three groups on the basis of its calyx morphology, although only members of group one can be found in Tanzania. Group one calyces have yellow sessile glands, the tube has short eglandular hairs and the lobes have short eglandular and glandular hairs. Group one specimens are found throughout the P. orthodonta distribution, and all the Tanzanian specimens belong to it. In the Flora Zambesiaca areas, there is more variation. Group two calyces are as group one but glandular hairs are absent, and the corollas reach the largest size (up to 17 mm, groups 1 and 2 up to 15 mm). Group three is only found in Malawi, and the calyces have a very dense patch of red sessile glands on the ventral side near the stem, but hairs as group one. The inflorescence tends to be longer and more lax in fruit, making it possible to see the inflorescence axis. Since the groups are similar in all other characters apart from the calyx, and they cannot be separated geographically, it is not plausible to recognise them formally.
Range: Zambia, Malawi, Mozambique and Zimbabwe Flora districts: T2 T ?4, T5 T6 T7 T8

Native to:

Malawi, Mozambique, Tanzania, Zambia, Zimbabwe

Coleus orthodontus (Gürke) A.J.Paton appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 1914 Hannington, J. [s.n.], Tanzania Pycnostachys orthodonta K000405966 Unknown type material
Jan 1, 1914 Buchanan, J. [873], Malawi Pycnostachys orthodonta K000405990 Unknown type material
Jan 1, 1914 Whyte, A. [s.n.], Malawi Pycnostachys orthodonta K000405991 Unknown type material
Robinson, E.A. [720], Zambia Pycnostachys orthodonta 15295.000
Carvalho [s.n.], Mozambique Pycnostachys orthodonta K000405992 Unknown type material
Busse [2834], Tanzania Pycnostachys orthodonta K000405967 Unknown type material
Bidgood, S. [6421], Tanzania Pycnostachys orthodonta K000468004

First published in PhytoKeys 129: 80 (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.

Flora of Tropical East Africa
Flora of Tropical East Africa

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

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.