Botanical Survey of India | Flora of India

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Tall evergreen trees or shrubs. Leaves alternate, simple, entire or denticulate along margins, mostly unequal-sided at base, glabrous or sometimes pubescent, penninerved with slender lateral nerves and usually with prominent, finely reticulate ultimate venation, short-petioled; stipules small, caducous. Inflorescences axillary or cauliflorous, fascicled, the flowers sometimes subsessile. Male flowers: sepals (2 or 3) 4 or 5, free, imbricate; petals absent; stamens 3 - 50, free; anthers 2-loculed, basifixed, extrorse or introrse; disc central, pubescent or glabrous, disciform, flat or with variously raised or crenate or lobulate margins, the lobes rarely produced outward embracing the bases of filaments. Female flowers: sepals 4 or 5 (- 6), same as in male but usually larger; petals absent; disc annular or occasionally shortly cupular; ovary 1 or 2 (- 3)- locular; ovules anatropous, 2 in each locule; styles obsolete or occasionally 1 - 3 mm long; stigmas mostly flabellate or sometimes circular or reniform. Fruits drupaceous, indehiscent, occasionally somewhat flattened; exocarp mostly fleshy and thick or sometimes thin; endocarp crustaceous or bony, sometimes sculptured; seeds solitary in each locule, ecarunculate; testa smooth; endosperm fleshy; embryo straight; cotyledons broad.

Mostly in Old World tropics, also in New World tropics, subtropical East Asia and South Africa, about 200 species; 20 species in India.

Literature. CHAKRABARTY, T., M. GANGOPADHYAY & N. P. BALAKRISHNAN (1997). The genus Drypetes (Euphorbiaceae) in the Indian subcontinent. J. Econ. Taxon. Bot. 21(2): 251 - 280, ff. 1 - 8.

Notes. The chromosome number reported so far is only in four African species, with the diploid number as 2n = 40 (Hans, Taxon 22: 591 - 636. 1973). Pollination is anemophilous or entomophilous. Pollen grains are prolate, tricolporate, tectate and with large endocolpus (Punt, Wentia 7: 1 - 116. 1962).

Almost all species yield timber of good quality and used for construction of houses or making furniture, agricultural implements or various other wooden materials.



KEY TO THE SPECIES


1 a. Styles 2 - 3 mm long 8. Drypetes indica
b. Styles obsolete 2
2 a. Ovary and fruits 1-locular (unknown in D. porteri); leaves usually smaller (up to 16 cm long) 3
b. Ovary and fruits 2-locular; leaves various, often larger 10
3 a. Leaves stiffly coriaceous, broadly rounded or obtuse or retuse at apex; minor nerves bullately impressed; fruits globose or fusiform, 6 - 8 mm in diam., fleshy 16. Drypetes sepiaria
b. Leaves chartaceous to thinly coriaceous, acuminate or at least narrowing towards apex; minor nerves not bullately impressed; fruits not as above 4
4 a. Leaves crenulate-serrulate or denticulate along margins 5
b. Leaves entire along margins 7
5 a. Endocarp of fruits sculptured with strong spiniform outgrowths 18. Drypetes sumatrana
b. Endocarp of fruits not sculptured 6
6 a. Fruits large, 16 - 18 x 10 - 13 mm, not flattened 1. Drypetes andamanica
b. Fruits small, ca 10 x 7 - 8 mm, often somewhat flattened 7. Drypetes gardneri
7 a. Minor nerves of leaves finely reticulate, forming polygonal areoles, never branching into veins of higher order 8
b. Minor nerves of leaves not so finely reticulate, forming more or less squarish or rectangular areoles, often branching into veins of higher order 9
8 a. Leaves 11 - 16.5 cm long, glossy; petioles 3 - 6 mm long, pulvinate at apex, mostly geniculate 6. Drypetes ellisii
b. Leaves 5 - 9 cm long, not glossy; petioles 9 - 11 mm long, pulvinate at apex, mostly geniculate 15. Drypetes porteri
9 a. Lateral nerves of leaves 6 - 9 pairs; male disc entire; female pedicels 4 - 5 mm long; fruiting pedicels 10 - 12 mm long; fruits mostly ovoid to ellipsoid, 1.7 - 2 cm long 20. Drypetes wightii
b. Lateral nerves of leaves 7 - 16 pairs; male disc lobulate; female pedicels 8 - 15 mm long; fruiting pedicels 20 - 26 mm long; fruits obovoid, 2 - 2.5 cm long 19. Drypetes venusta
10a. Inflorescences (at least partly) cauliflorous, on old wood 11
b. Inflorescences strictly axillary, on main leafy sho 14
11a. Midrib on upper surface of leaves clearly channeled or impressed 11. Drypetes longifolia
b. Midrib on upper surface of leaves flat 12
12a. Branchlets and leaves pubescent; leaves entire; fruits small (2 - 2.5 cm in diam.), on 10 - 12 mm long pedicels 12. Drypetes malabarica
b. Branchlets and leaves glabrous or glabrescent; leaves obscurely to prominently denticulate or serrulate along margins; fruits large (2.5 - 5 cm in diam.), sessile to subsessile 13
13a. Glomerules of flowers coralliform; stamens 15 - 20; male disc shortly cupular and ribbed, with thin raised margins 4. Drypetes confertiflora
b. Glomerules of flowers not coralliform; stamens 30 - 40; male disc disciform, not ribbed 14. Drypetes oblongifolia
14a. Leaves serrulate or denticulate along margins 15
b. Leaves entire along margins 16
15a. Leaves 13 - 15 x 4 - 5 cm, chartaceous; midrib flat above; fruits ovoid-ellipsoid, thin-walled 9. Drypetes jaintensis
b. Leaves (10-) 15 - 35 x 4.5 - 8 cm, coriaceous; midrib often slightly incised above; fruits oblong- ellipsoid to globose or transverse, thick-walled 17. Drypetes subsessilis
16a. Female and fruiting pedicels (fruits unknown in D. eglandulosa) longer, 5 - 15 mm long 17
b. Female (unknown in D. leiocarpa) and fruiting pedicels shorter, 0.5 - 5 mm long 19
17a. Leaves larger, 7 - 28 cm long, glossy; female and fruiting pedicels 5 - 10 mm long; fruits sub- cubical 3. Drypetes bhattacharyae
b. Leaves smaller, 5 - 10 cm long, not glossy; female and fruiting pedicels 10 - 15 mm long; fruits not sub-cubical 18
18a. Leaves brownish when dry; nerves and nervules prominent on the upper surface; fruits unknown (N E. India to Myanmar) 5. Drypetes eglandulosa
b. Leaves blackish when dry; nerves and nervules obscure or faint on the upper surface; fruits globose, 1.6 - 2 cm in diam., thick-walled (Nicobar Islands) 13. Drypetes microphylla
19a. Fruits glabrous, globose 10. Drypetes leiocarpa
b. Fruits pubescent, of various shapes 20
20a. Leaves often obscurely serrulate; midrib often slightly incised on the upper surface; male flowers 4 - 5 mm in diam.; stamens 3 - 4; female pedicels 0 - 2.5 (-5) mm long; fruits oblong- ellipsoid to globose or occasionally transverse 17. Drypetes subsessilis
b. Leaves always entire; midrib flat on the upper surface; male flowers ca 10 mm in diam.; stamens (6-) 8 - 15; female and fruiting pedicels 2 - 4 (-5) mm long; fruits subcubical or often transverse 2. Drypetes assamica


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