Dialium hydnocarpoides

Author: de Wit

Morphological description
Trees , medium- to large-sized up to c. 30 m, diameter at breast height up to 45 cm; buttresses relatively high; twigs greyish brown to dark brown, lenticellate, brownish hairy when young, glabrescent.

Leaves imparipinnate, including petiole (5-)7-20(-24) cm long; petiolules 2-4 mm. Leaflets (11-)15-17(-19), elliptic-oblong in middle part of leaf, ovate near petiole, (2.5-)3.5-6(-8.5) by (1.5-)2-3(-3.5) cm, subcoriaceous; apex rounded, obtuse or abruptly acuminate; base usually rounded; surfaces concolorous, rather dull, brownish hairy beneath, glabrescent; nerves (5-)6-9 pairs, rather fine, distinct, reticulation indistinct.

Inflorescence : Panicles terminal, the lower primary branches subtended by reduced or normal leaves, rachis (6-)9-15(-20) cm, densely brownish hairy; pedicels 1-2 mm.

Flowers white. Sepals 5, ovate-lanceolate, 3.5-4 by 1.5-2.5 mm, minutely hairy inside. Stamens 2, rarely 3; filaments 1-1.5 mm, glabrous; anthers 2.5-3 mm long, rather flattish on abaxial and adaxial sides, connective hairy on both sides. Ovary inserted on a narrow, flattish and patent-hairy receptacle, 1.5-2 mm long; style 1-1.5 mm long, slightly recurved at the top.

Fruits subglobose, sometimes slightly compressed. 1.5-2 cm in diameter; exocarp brittle, densely and rather persistently, brownish hairy.

Seeds orbicular, c. 9 by 8 mm; testa chocolate brown, shiny.

Malesia : S Sumatra, Borneo (Sabah, Kalimantan).

Primary forest, 20-60 m altitude.

Flowering from January to July; fruiting from April to June.

At a glance, the flowers of this species could be mistaken for Dialium platysepalum but dissection will show that the receptacle is narrow with a flattish top, and the anthers have a flattish (not V-channeled) abaxial side.