Hexalobus salicifolius
Evergreen tree of up to 35 m tall; dbh trunk up to 1 m, deeply channelled, (giving it the appearance of a bundle of columns); bark c. 6 mm thick, longitudinally fissured, peeling of in narrow, long papery flakes, brown to grey, quickly turning orange-brown when cut; twigs, leaves and petioles densely hairy when young. Leaves: petiole 1-3 mm long, 1-1.7 mm in diam., sparsely covered with appressed, brown hairs; leaf blade narrowly elliptic to ovate or obovate, 5-10 cm long, 1.5-3.5 cm wide, apex acuminate with a blunt tip, base cuneate, coriaceous, upper surface often greyish, glabrous, lower surface brown when dry, sparsely covered with appressed, light brown hairs c. 0.2 mm long; midrib usually covered with small, erect, white hairs above, covered with appressed, light brown hairs below; secondary veins 5-12 pairs, indistinct or distinct above, below distinct, at angles of 50-60º with the midrib; tertiary venation indistinct. Flowers 1-3 together on short shoots, fragrant; flower stalk 8-15 mm long; the part of the flower stalk below the articulation 3-7 mm long, c. 1 mm in diam., in fruit 2-2.8 mm in diam., often bearing 1 or 2 vegetative shoots; bracts 5-6, c. 5 mm long, 3 mm wide; the part of the flower stalk above the articulation curved, in flower 5-8 mm long, 1.5-1.8 mm in diam. and densely covered with appressed, rusty-brown hairs, in fruit 8-10 mm long, 2.1-3 mm in diam. and glabrous; buds ovoid to more or less globose, c. 7 mm in diam.; sepals 7-11 mm long, 4-7 mm wide, outside covered with rusty-brown, 0.1-0.8 mm long hairs, inside densely covered with curly hairs, basal part of sepal sparsely hairy or glabrous; corolla cream to yellow, basal rim dark purple, tube 2-4 mm long, lobes narrowly lanceolate, 17-30 mm long, 4-8 mm wide, rounded at apex, outer side with appressed, light-coloured, 0.1-0.8 mm long hairs, apical hairs shorter than basal ones, inside covered with appressed, c. 0.1 mm long hairs, base glabrous or sparsely covered with curly, fine, white, c. 1 mm long hairs; stamens numerous, narrowly obtriangular, c. 2 mm long, c. 0.5 mm wide, connective appendage flattened, slightly convex; carpels 3-4, 2-2.5 mm long, 1-1.5 mm wide, densely hairy; stigmas attached to the top of the ovary often bending in horizontal position, 1.2-2 mm long, 1.2-1.5 mm wide, divided in two lobes with the edges coiled inwards, hairy except on the inner and upper side. Monocarps 2-4, subsessile, ovoid to oblong, 6-9.3 mm long, 4-5.5 cm in diam., verrucose, densely covered with velutinous, rusty-brown, c. 0.1 mm hairs; seeds c. 12-15, biseriate, ellipsoid, slightly flattened, 22-31 mm long, 11–18 mm wide, 7-12 mm thick, light to dark brown, dull to shiny, raphe raised
Hexalobus salicifolius closely resembles H. crispiflorus and has been considered as a variety of the latter in for example Wilks et al. (2000), although that combination was never officially published. We, however, consider them here as two distinct species, in agreement with Le Thomas (1969). For differences between these two species we refer to the remarks below the treatment of H. crispiflorus.
Le Thomas (1969) mentions the presence at H. salicifolius in Ivory Coast (specimen Aké Assi 5962), but after close examination the specimen appeared to belong to H. crispiflorus.
Vulnerable: B2 ab(iii)(iv). Hexalobus salicifolius is represented by a moderate number of herbarium collections and has been recently collected (2005). In addition, several collections were made in protected areas, such as national parks (Lopé and Monts Doudou (Gabon)) and one forest reserve (Ototomo (Cameroon)). Even though the AOO is just 120 km2, its presence in protected areas as well as recent collections suggest a “vulnerable” status instead of an “endangered” one.
Southern Cameroon (Central and South Province), Gabon and southern part of Republic of the Congo (Kouilou region)
A species growing in primary and secondary tropical lowland and lower montane rain forest, occasionally in deciduous woodlands, mostly in periodically inundated forests and on river banks, from sea level to 1000 m altitude.