Monodora zenkeri
Lianescent tree to 6 m tall; d.b.h. unknown; outer bark dark greyish-brown with pale brown lenticels; young branches drying black, glabrous, rarely sparsely covered with short appressed hairs; old branches greyish to brown, with sometimes sparsely distributed white lenticels, glabrous. Petioles 2-4 mm long, 0.9-1.2 mm in diameter, glabrous, leaf lamina inserted on side, grooved adaxially. Leaf lamina 10-15 mm long, 8-14 cm long, length:width ratio 2.5-3, narrowly obovate to obovate or narrowly elliptic to elliptic, base rounded to obtuse, apex acuminate, acumen 3-6 cm long, papyraceous when young becoming coriaceous, glabrous; midrib raised but sunken towards the base, glabrous on both sides; secondary veins 10-13 pairs, uniformally curving upwards, glabrous. Flowers single, extra axillary or sometimes leaf-opposed, pendulous. Flowering pedicels 28-50 mm long, 0.5-1 mm in diameter, sparsely covered with short erect hairs. Upper bract inserted halfway up to subapically on the pedicel, 11-20 mm long; 10-13 mm wide, length:width ratio 1-1.4, broadly ovate to ovate, base decurrent, apex rounded to acute, glabrous, pale green; margins straight to slightly undulate, sparsely covered with short erect hairs. Sepals 11-17 mm long; 7-10 mm long, length:width ratio 1.5-2, ovate, base truncate-cordate, apex acute, covered with short erect hairs all over and on both sides, pale green; margins straight, covered with short erect hairs. Outer petals 35-45 mm long, 20-28 mm wide, length:width ratio 1.5-2, ovate, base truncate with two small lobes, apex acute to obtuse, glabrous to sparsely covered with short erect hairs on both sides, white or pale green tinged dark red; horizontally spreading, margins straight, covered with short erect hairs. Inner petals 9-13 mm long, 13-16 mm wide, length:width ratio 0.7-0.9, clawed triangular, base truncate to cordate, apex acute, glabrous inside, covered with short erect hairs in center outside, pale green with red spots; central parts of lamina appressed over the receptacle, distal parts reflexed outwards; margins straight, folded outwards, densely covered with short curly hairs; claw 4-7 mm long; 3-5 mm long, claw:inner petal ratio 0.3-0.5, glabrous, arched inwards. Receptacle ca. 4 mm in diameter, convex. Stamens in 9-10 rows, 0.9-1.1 mm long; connective shield ca. 0.2 mm long, covered with short erect hairs, those of innermost whorl not elongated over ovary wall. Ovary ca. 2 mm long, ca. 1 mm wide; stigma 1.5-2 mm in diameter, sparsely covered with short erect hairs. Fruits unknown.
Monodora zenkeri is distinct from other West-Central African species by the straight margins of the outer and inner petals, as well as the inner petals that are connivent at the center and not at the margins. In this respect it closely resembles the East African species M. junodii, from which it can be distinguished by the presence of the two minute lobes at the base of the outer petals, as well as differences in leaf shape and longer flowering pedicels.
EN B2ab(iv, iii). Monodora zenkeri is represented by only 8 collections in herbaria, and hasn’t been collected for 30 years (last collection in 1978). It is not found in any protected areas, and local logging threatens its habitat. The “endangered” status seems justified. However, given the lack of recent collections, it could quickly be upgraded to the “critically endangered” category.
Cameroon; in secondary and disturbed lowland rain forests; at 600-700 m altitude.