Key to the species of Memecylon with cordate leaves occurring in peninsular India and Sri Lanka

1. Leaves elliptic-orbicular in outline .................................................................. Memecylon orbiculare Thwaites (1859: 112)

- Leaves ovate, elliptic-ovate, ovate-oblong, lanceolate or oblong-lanceolate in outline ........................................................ 2

2. Leaves with conspicuous intra-marginal veins ...................................................................................................................... 3

- Leaves with obscure intra-marginal veins.............................................................................................................................. 6

3. Leaves with revolute margins ........................................................................... Memecylon revolutum Thwaites (1859: 111)

- Leaf margins flat .................................................................................................................................................................... 4

4. Flowers borne in sessile clusters on the branches below the leaves ..................... Memecylon hookeri Thwaites (1859: 113)

- Flowers in axillary and terminal pedunculate inflorescences ................................................................................................ 5

5. Branchlets terete; leaves up to 12 cm long; inflorescence to 4 cm long ....................................... Memecylon ponmudianum

- Branchlets winged; leaves 20–35 cm long; inflorescences 6–12 cm long......................................... Memecylon subramanii

6. Flowers fascicled on axillary or lateral tubercles................................................................................................................... 7

- Flowers in peduncled cymes.................................................................................................................................................11

7. Leaf margins revolute........................................................................................ Memecylon ovoideum Thwaites (1859: 112)

- Leaf margins flat .................................................................................................................................................................... 8

8. Leaves 15–40 cm long ............................................................................... Memecylon macrophyllum Thwaites (1859: 111)

- Leaves less than 15 cm long................................................................................................................................................... 9

9. Leaves ovate or elliptic-ovate, base semi-amplexicaul........................................................................................................ 10

- Leaves lanceolate, base not amplexicaul or semi-amplexicaul................ Memecylon depressum sensu Gamble (1919: 504)

10. Branchlets 4-angular; calyx funnel shaped ............................. Memecylon sessile Bentham ex Wight & Arnott (1834: 320) [ M. malabaricum (Clarke 1879: 559) Cogniaux (1891:1148), non Kosteletzky (1835: 1517)]

- Branchlets terete or subterete; calyx campanulate ................................................. Memecylon wightii Thwaites (1859: 113)

11. Inflorescence subterminal and axillary umbellate cymes; peduncle 1–2 cm long................................ Memecylon terminale

- Inflorescence an axillary or lateral short peduncled cyme; peduncle 0.5–1 cm long .......................................................... 12

12. Leaves ovate-oblong, obtuse at apex; calyx campanulate above the ovary ....... Memecylon sisparense Gamble (1919: 227)

- Leaves oblong-lanceolate, acuminate at apex; calyx tube above the ovary saucer-shaped ..................................................... ............................................................................................................................ Memecylon deccanense Clarke (1879: 560)