Stachyothyrsus Harms, Nat. Pflanzenfam. Nachtr. 1: 198. 1897.

Figs 88, 89, 92

Kaoue Pellegr., Bull. Soc. Bot. France 80: 464. 1933. Type: Kaoue stapfiana (A. Chev.) Pellegr. [≡ Oxystigma stapfiana A. Chev. (≡ Stachyothyrsus stapfiana (A. Chev.) J. Léonard & Voorh.)]

Type.

Stachyothyrsus staudtii Harms

Description.

Unarmed trees 20-25 (30) m; trunk not buttressed; brachyblasts absent; glabrous. Stipules small, caducous. Leaves bipinnate, rachis 4-20 cm; pinnae 2 pairs; leaflets 3-5 pairs per pinna, opposite, glabrous, venation reticulate. Inflorescences spiciform racemes, sometimes arranged in paniculate synflorescences; bracts triangular-rounded, persistent. Flowers small, whitish, fragrant, 5-merous, diplostemonous; calyx short, cupuliform; petals obovate-oblong; stamens dimorphic, the 5 antesepalous slightly longer than the 5 antepetalous (shorter), anther glands absent; pollen tricolpate monads; ovary short, 2-3-ovulate, style short, stigma slightly bilobed. Fruit dehiscent legume, curved, flat, 1-2-seeded. Seeds irregular shaped, dark.

Chromosome number.

Unknown.

Included species and geographic distribution.

Two species, restricted to the central-west coast of Africa in Ivory Coast, Liberia and Sierra Leone ( S. stapfiana J. Leonard & Voorhoeve), and Cameroon, Gabon, Equatorial Guinea and Congo ( S. staudtii) (Fig. 92).

Ecology.

Stachyothyrsus occurs in tropical rainforests, including swamps, along river banks, and secondary forests.

Etymology.

From Greek, Stachys (= spike) and thyrsus (= wand, panicle), in reference to the spicate inflorescences aggregated into showy panicles.

Human uses.

Stachyothyrsus stapfiana leaves are used for thatching, while its wood has only limited importance (Brink 2010).

Notes.

Stachyothyrsus is most closely related to Burkea (the genera have stamens arising at the insertion or just slightly above the ovary insertion), but they are easily distinguished by the opposite, less numerous and larger leaflets in Stachyothyrsus . In addition, Stachyothyrsus species occur only in rainforests along the west coast of Africa, whereas Burkea is widely distributed in African savannas and dry forests.

Taxonomic references.

Aubréville (1959); Hutchinson and Dalziel (1958); Savill and Fox (1967); Voorhoeve (1979).