Monodora Dunal, Monogr. Anon. 3: 79, 1817

Type species.

Monodora myristica (Gaertner) Dunal.

Description.

Trees, rarely shrubs or rarely lianas, 4-40 m tall, d.b.h. 6-100 cm; stilt roots or buttresses absent. Indumentum of simple hairs, or absent. Leaves: petiole 2-14 mm long, 1-2 mm in diameter, blade inserted on the side of the petiole; blade 4-50 cm long, 2-15 cm wide, elliptic or obovate or oblong or ovate, apex acuminate, acumen ca. 1 cm long; base cuneate to rounded, concolorous; midrib raised above; secondary veins 8 to 23 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, leaf opposed or extra axillary, 1 per inflorescence; pedicel 8-270 mm long, 1-2 mm in diameter; in fruit 25-350 mm long, 3-15 mm in diameter; bract 1, towards the upper half or middle of pedicel; sepals 3, valvate, free, 2-40 mm long, 2-17 mm wide, ovate or elliptic, apex acute or attenuate or rounded, base truncate, margins flat, undulate, wavy or crisped; petals basally fused, tube 2-8 mm long, inner and outer whorl differentiated, outer petals longer than inner; outer petals 3, 17-105 mm long, 6-40 mm wide, oblong or obovate or ovate, apex truncate, base truncate or with two small lobes, margins flat or wavy or crisped; inner petals 3, valvate, 9-35 mm long, 5-30 mm wide, cordate or rhombic or triangular to cochleate, apex acuminate to acute, base narrowed into a claw, claw 1-9 mm long; receptacle flat to strongly convex; stamens numerous, in 9 to 20 rows, 1-2 mm long, broad; connective discoid or elongated; staminodes absent; carpels fused into a syncarpous ovary, 1-5 mm long, stigma bilobed, slightly capitate. Fruit syncarpous, sessile, 35-150 mm long, 20-150 mm in diameter, globose or ovoid or conical, apex apiculate to rounded; seeds numerous, 9-22 mm long, 5-13 mm in diameter, ellipsoid or flattened ellipsoid; aril absent.

A genus of trees with 14 known species, from West, Central and East Africa. In Cameroon six species are known, one endemic.

Monodora, together with its sister genus Isolona, are unique in Annonaceae in having truly syncarpous ovaries, producing single fruits with unordered seeds, in contrast to other genera which have either uni- or biseriate placentation. Petals in Monodora are basally fused forming a short (not clearly visible) tube. The petals, however, are differentiated into inner and outer whorls, in contrast to Isolona (which has six equal lobes in a single whorl with a visible tube). In the vegetative state, Monodora and Isolona (together with Polyceratocarpous pellegrinii) are characterized by a raised leaf midrib on the upper side, in contrast to a sunken or flat midrib in all other genera found in Cameroon. Monodora species tend to have a whitish-grey wax indumentum on young leaves and fruits, which is especially noticeable in the common and widespread species M. myristica .

Taxonomy.

Couvreur (2009).