Coleus descampsii (Briq.) A.J.Paton

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: Congo-Kinshasa, Katanga, Lufonzo [Lufogo] R., Mar. 1896, Descamps s.n. (BR!, holo.)

Morphology General Habit

Perennial herb, 1.5–3 m tall, becoming woody below

Morphology Stem

Stems erect, branching, quadrangular, or rounded-quadrangular where woodier, grooved, pubescent with short eglandular hairs, also with red sessile glands

Morphology Leaves

Leaves opposite or quadrate, with densely leaved shoots arising from the axils, sessile blades linear to very narrowly elliptic to oblanceolate, 1.5–6 × 0.1–0.7 cm, wider and more variable near the base of the stem, often folded near apex, with small widely-spaced serrations, apex acute, base sessile, pubescent with eglandular hairs, sometimes sparsely so, the hairs more plentiful on venation beneath, also with deeply set red sessile glands

Morphology Reproductive morphology Inflorescences

Inflorescence dense, when in flower forming a narrowly conical shape, becoming more cylindrical in fruit, 55–140 × 15–20 mm flowers sessile in 1-flowered cymes bracts subtending entire inflorescence linear, 10–11 mm long, acute, deflexed in flower, pubescent with short eglandular hairs, persistent through flowering stage bracts subtending single flowers ± linear, 6–9 mm long, ciliate

Morphology Reproductive morphology Flowers Calyx

Calyx with tube ± 1 mm long at anthesis, outer surface with eglandular hairs, these more conspicuous in the fruiting inflorescence, also with scattered red sessile glands, inner surface with 0.5 mm long triangular scales present between calyx lobes lobes 5, subulate, ± equal, ± 3 mm long fruiting calyx with tube 4–5 mm long, ventrally gibbous, somewhat inflated, lobes 3–5 mm long

Morphology Reproductive morphology Flowers Corolla

Corolla blue, 10–12 mm long tube with scattered eglandular hairs, very narrow and parallel-sided for ± 4 mm, then curving sharply downwards and broadening for ± 3 mm before opening out into two lips posterior lip shorter than anterior, 2.5–3 mm long, with eglandular hairs anterior lip 5–6 mm long, ± 2 mm deep, with eglandular hairs on the front of lip

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens connate for ± 1 mm, posterior pair exserted for ± 1 mm, anterior pair barely exserted near end of lip

Morphology Reproductive morphology Fruits

Nutlets ± 1.5 mm long.

Ecology

Wet grassland; altitude unknown

Conservation

Least concern; widely distributed

Note

The names P. pallidecaerulea and P. linifolia are synonymised here because they fall within the variation described under P. descampsii. Pycnostachys descampsii has leaves that are variable in shape, usually opposite but not obviously so because there are densely leaved shoots in each leaf axil. The leaves have deeply set red sessile glands and short stiff hairs that are ± erect, and the venation is quite parallel in appearance. The distribution is centred on the Kundelungu Mts in Congo-Kinshasa, but reaches Cameroon in the west, and stretches east to Tanzania where it apparently mixes with P. parvifolia, which is centred in Zambia but stretches north from there. As a result, specimens from Tanzania appear to be somewhat intermediate (see notes under P. parvifolia). Without further material, it is only possible to highlight this as a problem, and it is likely that most specimens from Tanzania will be difficult to determine. Kahauruananga, Kibuwa & Mungai 2687, collected between Bulimba and Lukoma, Bidgood et al. 5768, and Bidgood et al. 5523 collected from Urambo area, are anomalous collections from T 4 that have many very narrow leaves that resemble pine needles, however they match the typical form in all characters of the inflorescence so are included here.

Distribution

Range: Cameroon and Congo-Kinshasa (Katanga) Flora districts: T4 (intermediates with P. parvifolia in T 7)