Medium to large-sized, resinous trees with straight boles, buttressed bases and dome-shaped or flat crowns; bark pale or dark grey to orange brown., sometimes pink
brown, shallowly flaked in patches, more or less prominently and densely verrucose-lenticellate. Leaves coriaceous, rarely thin, margin usually sinuate towards apex; nerves prominent beneath, straight, curved only towards margin, tertiary nerves scalariform; petioles distinctly geniculate, stout; stipules large, hastate to lorate, obtuse, more or less succulent, caducous. Inflorescences few-flowered, short, stout, zig-zag, somewhat irregularly, sparingly branched racemes. Flowers white or pink, large. Calyx 5-lobed, lobes valvate, two longer ones oblong to spathulate, more or less distinctly 3-nerved and developed into erect, strap-shaped or oblong, larger wings in the fruit, other three lobes remaining short and forming a crown round apex of the nut. Corolla lobes large, white or cream-coloured with a more or less dark crimson or pink stripe down the centre, narowly oblong. Stamens 15 to many, persisting in a ring around ovary after petals fall oft; filaments of variable length, broad, compressed, connate at base, tapering gradually
and filiform below the anther; anthers long, linear, tapeing apically with 4 pollen sacs, inner two somewhat shorter than outer two; appendage of connective short, stout to filiform, glabrous. Ovary enclosed in calyx tube, the apex ovoid to conical, densely Puberuient; stylopodium cylindrical to filiform, densely puberulent, narrowing into a glabrous, filiform style. Fruit large, nut-like, enclosed in calyx tube with two lobes accrescent.
Sri Lanka and India, eastwards to Indo-China, Sumbawa, Borneo and the Philip-pines, ca 80 species; 10 in India.
Literature.
As of family.
KEY TO THE SPECIES
1a. Mature fruiting calyx tube angled, ribbed and winged
2
b. Mature fruiting calyx not angled, ribbed or winged
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2a. Calyx tube with angles very narrowly winged
3
b. Calyx tube with angles widely winged
4
3a. Leaves glabrous on both surfaces; lateral nerves straight; flowers,5 - 6.3 cm across; two enlarged fruiting calyx lobes oblong-spathulate, 3-nerved from three-quarters of their length or throughout, an additional pair making 5-nerved towards base, glabrous, three short lobes elliptic
b. Leaves densely tomentose with fine stellate hairs on both surfaces when young, becoming glabrous or nearly so above when old; lateral nerves ascending; flowers ca 1.8 cm across; two enlarged fruiting calyx lobes linear-oblong, 3-nerved, sparsely stellate-hairy, three short lobes suborbicular
b. Bark pale bluish-grey outside, not lenticellate, closely vertically fissured; leaves thinly ciliate along the margins, lateral nerves straight and parallel; calyx velvety outside
8a. Fruits pointed towards both the ends, densely greyish dull brown silky outside; corolla lobes reaching 6.3 cm long, falcate; leaves sparsely pilose when young, glabrous above except along midrib when mature, stellate-pubescent beneath nerves
b. Fruits globose, ovoid or ellipsoid, blunt at apex, smooth and glabrous, glaucous; corolla lobes up to 3 cm long, linear or linear-oblong; leaves glabrous on both surfaces
9
9a. Fruits globose to subturbinate, without striations, linear wings of the fruit abruptly constricted and revolute at bile, strongly 3-nerved, nearly the whole lenath with an additional pair of longitudinal nerves more or less developed; bark dark grey, peeling off in flakes
b. Fruits globular or ovoid or ellipsoid, smooth with marked striations; linear wings of fruit not as above but with one prominent median nerve and 2 basal smaller nerves; bark greyish brown, vertically fissured and irregularly flaking or cracking, rarely smooth, exfoliating in strips
