Leucas densiflora Vatke

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. Leucas, G. Bramley. Flora of Tropical East Africa. 2009

Type

Type: Tanzania, Zanzibar, Kokotoni, Hildebrandt 999 (B†, holo.; BM!, BREM, K!, L, W, iso.)

Morphology General Habit

Erect herb or small shrub, 0.3–2 m high, with branching, scrambling or straggling stems

Morphology Stem

Stems pubescent with patent or downward curving hairs, becoming less pubescent and woody

Morphology Leaves

Leaves petiolate; blades ovate to narrowly ovate, (6–)8.5–14 × (2.5–)4–7 cm, margins serrate to crenate-serrate, the serrations usually with tiny mucronate tips, apex shortly acuminate, base ± truncate then shortly attenuate, upper surface lightly pubescent with appressed eglandular hairs, lower surface pubescent, the hairs spreading and more plentiful on venation, the hairs on the lamina shorter and erect, also with scattered yellow sessile glands; petioles 15–50 mm long, pubescent with patent hairs

Morphology Reproductive morphology Inflorescences

Inflorescence of 3–7 verticils spaced 0–35 mm apart, usually forming a dense cluster, occasionally further apart near the base; verticils very congested with many flowers in each cyme; pedicels ± 1 mm; bracteoles linear, 4–8 mm long, apex spinescent, pubescent, with occasional yellow sessile glands

Morphology Reproductive morphology Flowers Calyx

Calyx funnel-shaped, slightly longer and more concave on the anterior side, 6–10 mm long at anthesis, outer surface pubescent especially along vein ridges, with yellow sessile glands, inner surface with short appressed hairs; throat ± symmetric; lobes 10, subequal, the central lobes on the posterior and anterior sides ± 2 mm long, the others ± 1 mm long, triangular at base then subulate, with short eglandular hairs

Morphology Reproductive morphology Flowers Corolla

Corolla white, 15–16 mm long; tube 7–8 mm long, lower half ± glabrous, upper half with appressed hairs, inner surface with patches of short glandular hairs leading to an undulate band of glandular hairs halfway down the tube; posterior lip 7–8 mm long; anterior lip 7–8 mm long, inner surface with patches of minute glandular hairs/papillae, outer surface pubescent except towards the lobe margins

Morphology Reproductive morphology Fruits

Nutlets 2–2.5 mm long, glandular upper surface.

Ecology

Clearings in coastal to submontane forest and associated bushland, secondary vegetation in old cultivations, grassy roadsides; near sea level to 2100 m

Conservation

Least concern; habitat unlikely to be in decline

Note

In L. densiflora the inflorescence usually forms a few verticils all congested together, and this is the major character distinguishing it from the other species in the ‘ deflexa’ group, since the verticils in those species are normally spaced out along the inflorescence axis. In addition, the calyx of L. densiflora is more symmetric at the mouth than the other species. There is apparently much variation in leaf size within this species.

Distribution

Range: Not known elsewhere Flora districts: T3 T6 T7 Z