Xanthophyllum

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Xanthophyllum

Description

Shrubs or trees. Leaves alternate (or spiral), sometimes shifted-decussate, stalked, nearly always with glands beneath, mostly near base of blade. Inflorescence axillary, branched or sometimes unbranched, panicle- or raceme-like. Flowers solitary or in lower half with 3 (rarely more) together. Sepals 5, free, usually slightly unequal, usually caducous after flowering. Petals 5, usually unequal, free; Stamens nearly always 8, rarely 7, 9, or 8-10; Fruit indehiscent (or very rarely irregularly 2-valved, not in Mal.), globular or rarely ellipsoid, c. 1-15 cm, usually with a hard pericarp. Seed(s) 1 or 4-20, inappendiculate, glabrous;

Distribution

Asia-Temperate: Hainan (Hainan present), Asia-Tropical, Australasia: Queensland (Queensland present), Austro-Malesia present, N. Queensland present, S. China present, tropical Southeast Asia present
About 94 species in tropical Southeast Asia, northwards to S. China and Hainan, throughout Malesia to Australia (N. Queensland); 76 spp. do not occur outside Malesia; 2 are endemic to Queensland.
Not a single species crosses WALLACE'S plant-geographical demarcation line. Although only 7 spp. occur east of this line, at subgeneric level the greatest variation is found there. For that reason it is assumed that the genus originated in Austro-Malesia.

Notes

From the subdivision of the genus it appears that both the fruit and seed, and the flower structure are important for specific distinction, in addition to vegetative characters. Unfortunately the mature fruit is yet unknown in several species (spp. 4, 16, 25, 34, 35, 36, 37, 38, 41, 51, 52, 58) and flowers are unknown from spp. 40, 49, 61, 67, 68, and 76. Besides, specimens in fruit seldom carry flowers too, and the reverse. These factors have complicated the key and necessitated to enter many species twice or even thrice.

Citation

MEIJDEN 1982 – In: Leiden Bot. Ser.
CHODAT 1929 – In: Merr., Pl. Elm. Born.: 133
NG 1972 – In: Tree Fl. Mal.: 352
HUTCH. 1967 – In: Gen. Fl. Pl.: 339
Roxb. 1896 – In: E. & P., Nat. Pfl. Fam. 4: 343
GAGNEP. 1909 – In: Fl. Gén. I.-C.: 242
GAGNEP. 1908 – In: Desv., J. Bot. 21: 241
CHODAT 1896 – In: Bull. Herb. Boiss.: 254
BENN. 1872 – In: Fl. Br. India: 208
Blume 1825: Bijdr.: 60