Trigonobalanus

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Trigonobalanus

Description

Trees. Leaves spirally arranged or in whorls of 3. Stipules extra- or inter-petiolar. Inflorescence catkin-like, male, female, androgynous or mixed. Fruit trigonous in cross-section, ovoid-triangular in outline;

Distribution

Asia-Tropical: Borneo present; Malaya (Peninsular Malaysia present), Central Celebes present, Mts Doi Chang and Doi Nang Ka, in Chieng Mai Prov., ±19° N, 99°E present, N. Siam present
Two species, one in N. Siam (Mts Doi Chang and Doi Nang Ka, in Chieng Mai Prov., ±19° N, 99°E) and one in Malesia: Malay Peninsula, Borneo, and Central Celebes. .

Notes

Through the paper by D. H. Mai on the Tertiary fossils of the genus in the Eocene in Europe () it has become clear that the two living species of the genus in West Malesia and Thailand are relicts of a former much larger range. T. doichangensis, hitherto only known from Thailand, has now also been recorded from Yunnan ().
This conclusion is now unexpectedly confirmed by the find of a third living species in the mountains of the National Park of Colombia (NW. South America). G. Loza- no-C, J. I. Hernandes-C& J. E. Henao-S published this as T. excelsa nov. sp. (). It grows in mountain forest at 1550-1800 m, as a large tree, 20-40 m high. Its leaves are scattered, as in the Thailand-Yunnan species. It is clear that the genus once had an ancient, large L Eurasian range. It should also occur in the fossil state in the southern U.S.A.

Citation

FORMAN 1964 – In: Kew Bull.: 381
FORMAN 1967 – In: Kew Bull.: 331