Horsfieldia polyspherula

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Horsfieldia polyspherula

Description

Tree 4-35(-40) m. Leaves thickly membranous to chartaceous, very brittle, (elliptic-)ovate-oblong to oblong-lanceolate, 7-28 by 2.5-9 cm, base ± rounded or usually attenuate, apex acute-acuminate; Inflorescences with sparse to dense woolly hairs 0.6 mm long, sometimes glabrescent; Fruits 1-6 per infructescence, subglobose or ellipsoid, apex rounded, base rounded or slightly attenuate, 1.9-6 by 1.4-5 cm, glabrous, not lenticel-like tuberculate;

Distribution

Asia-Tropical: Borneo present; Malaya (Peninsular Malaysia present); Philippines (Philippines present); Sumatera (Sumatera present), Luzon present, Mindanao present, Palawan present
Malesia: Sumatra, Peninsular Malaysia, Borneo, Philippines (Luzon, Mindanao, Palawan; only var. polyspherula); 0-1100 m altitude.

Taxonomy

Horsfieldia polyspherula is a variable species of a complex to which belong closely related species such as H. laticostata, H. oligocarpa, and H. tenuifolia (all from Borneo), H. brachiata (Sumatra to Borneo), and H. majuscula (Peninsular Malaysia). Variability is found in the thickness of twigs, size and texture of leaves, density of indumentum on leaf buds and twig apex, and especially in fruit size and thickness of the pericarp. On the basis of mainly fruit characters, arbitrarily three rather heterogeneous varieties can be recognized. There are slight differences in the size of the male perianth, mainly on account of the varying thickness of its lobes; the number of thecae is possibly the same in all three varieties.

The anthers have two rather widely separated, almost mutually free thecae, giving the impression as if there are twice as many anthers than actually are present.

Citation

W.J. de Wilde 2000 – In: Tree Fl. Sabah & Sarawak: 383