Equilabium rungwense (A.J.Paton) Mwany. & 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. Flora of Tropical East Africa. 2009

Type

Typus: Tanzania, Rungwe District: NW slope of Mt Rungwe on N slope of Mwashitu Hill, above Sinihi stream, Mwasumbi 16222 (K!, holo. DSM!, MO!, iso.)

Morphology General Habit

Aromatic perennial slightly viscid herb with stems 1.5–3 m tall

Morphology Stem

Stems ascending, quadrangular, branching in the inflorescence, basal parts not seen, pubescent with short glandular patent hairs and pale sessile glands

Morphology Leaves

Leaves spreading to ascending, petiolate; blades cordate to ovate, 9–12 × 10 cm, margin irregularly dentate with teeth themselves toothed, weakly revolute, apex acute to acuminate, base cordate to deeply so, pubescent or sparsely so, with pale sessile glands; petiole 7–10 cm long

Morphology Reproductive morphology Inflorescences

Inflorescence with several branches with 6-flowered verticils 15 mm apart or less, with bracts subtending 3-flowered shortly pedunculate or sessile cymes; bracts with lowermost sometimes leaf-like, but mostly entire or few-toothed and much smaller than leaves, ovate, 3–10 mm long, persistent; peduncles 0–2 mm long; pedicels 2–5 mm long

Morphology Reproductive morphology Flowers Calyx

Calyx 2–3 mm long, pubescent, with red sessile glands; fruiting calyx 7–9 mm long, shortly tubular with pedicel attached centrally at base of calyx; throat truncate; posterior lip ovate, shortly decurrent at least in flower, curving upwards, mucronate at apex; lateral and median lobes of anterior lip lanceolate with the median slightly longer and narrower

Morphology Reproductive morphology Flowers Corolla

Corolla white with scattered hairs and pale sessile glands on lobes and tube, 10–12 mm long; tube 6–8 mm long, with a single bend; posterior lip erect, equal to anterior; anterior lip 4 mm long, ascending, glabrous within, not frilled at apex

Morphology Reproductive morphology Flowers Androecium Stamens

Staminal filaments free

Morphology Reproductive morphology Fruits

Nutlets pale brown, ovoid with darker raised areas, 1.5 mm long, producing mucilage

Figures

Fig 42, p 255

Ecology

Forest; 2100 m

Conservation

Critically endangered, CR B2 a,b (i,ii,iii); known only from the two cited specimens (AOO 2.16 km2, based on cell width of 1.04 km; number of cells 2)

Note

Similar to P. wollastonii in the shape of the corolla tube which is much wider at the base and less strongly sigmoid than that of P. laxiflorus, P. kamerunensis, P. petiolaris, P. stolzii and P. glandulosus (fig. 42/2, 3 B & C). Differs from P. wollastonii in having pale rather than reddish sessile glands, a longer fruiting calyx and often longer corolla. Also similar to P. glandulosus but differs in having more deeply toothed leaves, shorter pedicels and in having white rather than blue flowers. Superficially similar to P. sylvestris but differs in having an equally lobed corolla, rather than a long anterior lobe and short posterior lobe, and more strongly toothed, cordate leaves.

Distribution

Flora districts: Known only from Mt Rungwe Flora districts: T7