Oroxylum

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Oroxylum

Description

Glabrous tree, robust in all its parts. Leaves 2-3(-4)-pinnate, all nodes with in sicco shrinking articulations; Flowers very large, fetid, nocturnal, in large terminal racemes (by exception in a thyrse). Stamens 5, subequal, all fertile; Ovary with rows of ovules in both cells. Capsule flat, very large, sword-shaped, linear; Seeds large in rows;

Distribution

Asia-Temperate: China South-Central (Yunnan present), Asia-Tropical: Philippines (Philippines present); Sulawesi (Sulawesi present), Ceylon present, Deccan present, Himalayas present, Kwangsi present, Kweichou present, S. China present, SE. Asia present, Setchuan present, Timor present
Probably monotypic. From Ceylon, the Deccan and Himalayas through SE. Asia (also in S. China: Yunnan, Kwangsi, Setchuan, Kweichou) and Malesia eastwards to the Philippines, Celebes, and Timor. .

Taxonomy

A second species has been described, raised from seed, collected by A. HENRY in Yunnan, in 1889, in the Arnold Arboretum, and named O. flavum REHDER (). REHDER discriminated this from O. indicum chiefly by the sulphur yellow colour of the nearly symmetrical flowers, the plain not toothed or crisped corolla lobes, the splitting calyx, and the oblong leaflets.
Several of these characters are not valid, especially if we take into consideration that REHDER'S plant was an unbranched sapling of 3 m high. In such saplings the leaves are always somewhat longer and thinner. The sulphur-yellow corolla is also rarely found in O. indicum from where I described it (1928) as var. citrinum STEEN. on a cultivated specimen at Bogor so annotated by J. J. SMITH (C.H.B. XV.K.B.IX-11). The calyx is indeed different from that in O. indicum, in being thinner and having 5 faint ribs, but it is lobed by tearing, and this is also sometimes found in fruiting specimens of O. indicum. The corolla in O. flavum is also regular and somewhat smaller than usual but an examination of the type showed an exactly similar occurrence of hairs at the anther bases, the patelliform glands outside and the granular-glandular hairs inside. Remains the plain, entire corolla lobes, and an other character figured by REHDER but not mentioned by him, viz that the inflorescence is not a raceme, but a thyrse, with the lower stalks 5-flowered in double triads and the upper ones in simple triads, a situation never recorded or seen by me in O. indicum. I cannot well account for these two differences, but they could be due to cultivation; in our experience tropical plants in hothouses often deviate from those in the wild, certainly in first-flowering saplings.

Citation

VENT. 1928 – In: Bull. Jard. Bot. Btzg: 181
BUREAU 1864: Mon: 45: t. 9
STEEN. 1927: Thesis: 816
DC. 1845 – In: Prod.: 177
K.SCH. 1894: p. 225. – In: E. & P., Nat. Pfl. Fam. 4: l.c. 212 in clavi