Memecylon sect. Buxifolia, R. D. Stone

Stone, Robert Douglas, 2022, Revised treatment of Memecylon section Buxifolia (Melastomataceae) in Madagascar, Candollea 77 (2), pp. 173-191 : 174-175

Key to the species of Memecylon sect. Buxifolia in Madagascar

1. Internodes between normal leaves generally 1–3(–8) cm long; “aphyllous” nodes generally present and alternating with the leafy nodes; leaves generally at least 2 × 1 cm ... ..................................................................................... 2

1a. Internodes 0.2 –1.5 cm long; most or all nodes bearing normal leaves (“aphyllous” nodes completely lacking or nearly so); leaves <2 × 1 cm ......................................... 7

2. Leaves generally <2 cm wide ...................................... 3

2a. Leaves generally> 2 cm wide ...................................... 5

3. Leaves narrowly elliptic or oblanceolate, (3.2–)4–5.2 × 0.5– 0.9(–1.2) cm, 4.5–7 times longer than broad ..................... ......................................................... 5. M. leptophyllum

3a. Leaves elliptic to elliptic-lanceolate or oblanceolate, mostly 2.5–4 × 1–1.7 cm, 2–3 times longer than broad ... ..................................................................................... 4

4. Leaves subcoriaceous, generally broadest above the middle, base ± angustate .................... 3. M. angustatum

4a. Leaves coriaceous, generally broadest at the middle or below, base cuneate ............................. 4. M. buxifolium

5. Young branchlets terete; leaves obovate to broadly elliptic, mostly 5.5–6.5 × 2.5–3.3 cm .............. 2. M. amplifolium

5a. Young branchlets quadrangular; leaves ± oblanceolate or if broadly elliptic then less than 4.5 cm long ............... 6

6. Leaves broadly elliptic to suborbicular, (3.2–)3.8–4.2 × 2.3– 2.9(–3.2) cm, base ± rounded ............... 1. M. ambilobense

6a. Leaves ± oblanceolate, (4.4–)5.2–7.4(–8.9) × 1.8–2.8(–3.5) cm, base attenuate .......................... 8. M. oblanceolatum

7. Leaves broadly elliptic to suborbicular, apex vaguely obtuse-acuminate ................................. 9. M. reductum

7a. Leaves narrowly elliptic to elliptic-lanceolate, apex acutecuspidate ...................................................................... 8

8. Leaves 0.5–0.7 × 0.2–0.25(–0.3) cm ............................... ........................................................ 6. M. minutifolium

8a. Leaves 1.6–1.8(–1.9) × 0.6–0.7 cm ....... 7. M. multinode