Memecylon, Stone & Mona & Ramdhani, 2017

Stone, Robert Douglas, Mona, Imercia Gracious & Ramdhani, Syd, 2017, Revised treatment of Mozambican Memecylon (Melastomataceae-Olisbeoideae), with descriptions of four new species in M. section Buxifolia, Phytotaxa 331 (2), pp. 151-168 : 165

Key to the species of Memecylon in Mozambique

1. Bark thick, deeply longitudinally fissured; branchlets with all nodes bearing normal leaves; leaf apices rounded to truncate or emarginate; petals subdeltate-acuminate with apex sharply acute; anther connectives purple; fruits ovoid-ellipsoid, 12–14 × 6–8 mm. In Mozambique confined to “miombo” woodland in NW Niassa Province (M. sect. Obtusifolia )..................... M. flavovirens

-. Bark thin, finely longitudinally fissured; branchlets with successive nodes alternating between normal leaves and reduced, ofteninflorescence-bearing bracts; leaf apices rounded to obtuse or ± acuminate; petals subrhomboid with apex rounded to subacute (acuminate in M. incisilobum ); anther connectives whitish or yellow; fruits ± globose in some species, ovoid to ellipsoid or obovoid in others, 8–18 × 7–14 mm (M. sect. Buxifolia )...................................................................................................................2

2. Leaf apices obtuse to rounded or ± broadly and obtusely acuminate, the acumen when present mostly 2–4 mm long....................3

-. Leaf apices ± distinctly acuminate, the acumen 3–8.5 (–11) mm long..............................................................................................6

3. Leaf-blades 1.5–4.5 × 0.5–2.7 cm; cymes up to 12-flowered, on peduncles up to 6 mm long. Known only from Magaruque Island near Vilanculos (Inhambane Province)................................................................................................................... M. insulare

-. Leaf dimensions as above or larger, 1.75–7 × 1–4 cm; cymes 1–3-flowered, on peduncles ca. 2 mm long.....................................4

4. Leaf-blades 4–7 × 2–4 cm; lower leaf surface vivid yellowish green; fruits ovoid, 18 × 14 mm. Coastal forests of N Mozambique (Nampula & Cabo Delgado provinces) ................................................................................................................................. M. torrei

-. Leaf-blades smaller, 1.75–5.5 × 1–3.3 cm; lower leaf surface pale green; fruits as above or smaller, 9–18 × 7–14 mm .................5

5. Leaf-blades mostly 3.5–5.5 × 1.8–3.3 cm; fruits ovoid to broadly pyriform, 18 × 14 mm. In Mozambique known only from the Namacubi coastal dry forest near Quiterajo (Cabo Delgado Province) ....................................................................... M. rovumense

-. Leaf-blades 1.75–3 × 1–1.75 cm; fruits elliptic to obovoid, 9–10.5 × 7–8 mm. Known only from the Namparamnera coastal dry forest near Quiterajo (Cabo Delgado Province) ...................................................................................................... M. aenigmaticum

6. Leaf-blades elliptic, mostly 5–7 × 2.5–3.5 cm; cymes borne mostly at the defoliated nodes of older branchlets, on peduncles mostly 5–10 (–13) mm long, up to 9-flowered; hypantho-calyx broadly cupuliform and with calyx-lobes scarious and regularly incised ± to the base; corolla in bud sharply apiculate; fruits with calycinal crown thickened and collar-like with lobes curved inwards. Coastal forest remnant in S Mozambique (Gaza Province).......................................................................... M. incisilobum

-. Leaf-blades ovate, dimensions ± smaller (mostly 3–6 × 1.5–3.2 cm); cymes mostly axillary and at the bracteate nodes alternating with those bearing fully developed leaves, on peduncles 1–7 mm long and usually 3-flowered; hypantho-calyx obconic, the margin slightly and obtusely 4-lobed; corolla in bud subacute; fruits with calycinal crown not thickened and collar-like, lobes spreading. Mountains of N Mozambique (Nampula & Zambézia provinces) at 1600–1700 m elevation.................. M. nubigenum