Coleus goetzenii (Gürke) A.J.Paton

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/111325504/111325510

Conservation

LC - least concern

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

Type: Rwanda, Virunga Mts, Goetzen 98 (B†, holo.)

Morphology General Habit

Shrub 1.5–5 m tall, apex herbaceous

Morphology Stem

Stems erect, branching, quadrangular, or rounded-quadrangular where woodier, pubescent with very short adpressed eglandular hairs and red sessile glands

Morphology Leaves

Leaves opposite, petiolate; blades narrowly ovate, 6–13 × 2–5 cm, closely crenate-serrate, apex acuminate, base obtuse or rounded, sometimes asymmetrically so, with red sessile glands, pubescent with very short adpressed eglandular hairs, these scattered above and more plentiful on margins and venation beneath, venation conspicuous; petiole 12–30 mm long, pubescent and with red sessile glands

Morphology Reproductive morphology Inflorescences

Inflorescence dense, when in flower forming a conical shape, tapering at the apex and becoming lax, in fruit 45–80 × 15–22 mm; bracts subtending entire inflorescence narrowly ovate, 15–25 mm long, acute, enclosing buds then becoming deflexed in flower, pubescent, persistent through flowering stage; bracts subtending single flowers linear, 5 mm long, pubescent, ciliate

Morphology Reproductive morphology Flowers Calyx

Calyx with tube ± 1 mm long at anthesis, outer surface with short adpressed eglandular hairs and yellow and red sessile glands, inner surface with 0.5 mm long triangular scales present between calyx lobes; lobes 5, subulate and ± equal, 4–5 mm long, with very short hairs near the base; fruiting calyx with tube 4–5 mm long, ventrally gibbous, lobes patent but slightly recurved, becoming thicker and more rigid, 6–9 mm

Morphology Reproductive morphology Flowers Corolla

Corolla blue to purple, 13–14 mm long, with scattered very shortadpressed eglandular hairs and red and yellow sessile glands; tube very narrow and parallel-sided for ± 4 mm, then curving sharply downwards and broadening for ± 4 mm before opening out into two lips; posterior lip shorter than anterior, ± 2 mm long; anterior lip 6–7 mm long, 3–4 mm deep

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens connate for ± 2 mm, exserted for 1–2 mm

Morphology Reproductive morphology Fruits

Nutlets not seen.

Ecology

Bamboo- Hypericum forest; dry rocky ridge with grass and shrubs; 2600–3300 m

Conservation

In a protected area but possibly threatened due to small area and encroachment

Note

Apparently endemic to the Virunga mountains, P. goetzenii can be recognised by the lax extension to the inflorescence and the very short pubescence on the lower leaf surface and calyx. In addition, it often has an asymmetric leaf base. Probably closest to P. erici-rosenii from which it can be distinguished by its tapered inflorescence axis, lack of conspicuous scales and longer, less pubescent calyx lobes.

Distribution

Range: Rwanda and Congo-Kinshasa (Virunga Mts). Flora districts: U 2 (Virunga Mts)