Ocimum centraliafricanum R.E.Fr.

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

Types: Zambia, near R. Kalungwishi [Kalungwisi], R.E. Fries 1166 (UPS, syn.) & near Mbala, Msisi, R.E. Fries 1282 (UPS, syn.)

Morphology General Habit

Aromatic perennial herb with several stems arising from a thick woody rootstock, 15–75 cm tall

Morphology Stem

Stems erect, quadrangular, sparsely branched, pubescent with antrorse hairs

Morphology Leaves

Leaves opposite or rarely ternate, ascending, sessile; blade 2–6 × 0.2–2.5 cm, narrowly to broadly elliptic or narrowly obovate, entire or distally serrate, slightly revolute or flat, apex acute to rounded, base cuneate, glabrous or sparsely pubescent, glandular-punctate

Morphology Reproductive morphology Inflorescences

Inflorescence condensed, with 6-flowered verticils usually touching in flower, up to 2 cm apart in fruit; bracts linear to ovate, 3–4 mm long, erect above forming a terminal coma, soon deciduous, scar forming a bowl-shaped nectary; pedicels 2–3 mm long, ascending, flattened

Morphology Reproductive morphology Flowers Calyx

Calyx 4.5–6 mm long at anthesis, pubescent on tube and posterior lip; posterior lip purplish, obovate, mucronate; lateral lobes of anterior lip truncate, tomentose overall, the median lobes small, subulate-aristate; fruiting calyx 8–10 mm long

Morphology Reproductive morphology Flowers Corolla

Corolla white, pink, purple or bluish, 6–11 mm long; tube 4–6 mm long, straight or slightly curved, dorsally gibbous, abruptly dilated at throat; lobes of posterior lip with a few small teeth; anterior lip horizontal, concave around filaments

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens exserted 10–18 mm

Morphology Reproductive morphology Fruits

Nutlets pale brown, broadly ovoid, 2 mm long, smooth, producing mucilage when wet

Figures

Fig 23: 3, p 140

Ecology

Montane grassland and Brachystegia woodland; 1650–2700 m

Conservation

Least concern

Note

O. centraliafricanum may be confused with O. obovatum var. obovatum, but can be distinguished by the tomentose lateral lobes of the calyx. It can also be distinguished from var. obovatum by the following characters which are difficult to observe on herbarium specimens: the corolla tube tends to be equal to rather than longer than the calyx tube and the posterior lip is longer in proportion to the tube. The lateral veins on the leaves of O. centraliafricanum tend to form a more acute angle with the midrib than in var. obovatum, but there is no clear discontinuity in this character. This species is often an indicator of copper-bearing soils.

Distribution

Range: Congo-Kinshasa, Zambia, Zimbabwe Flora districts: T4 T7