Author: Linnaeus
Morphological description (indum Dialium compl FT22)
Trees , up to 40 m high, diameter at breast height up to 1 m; butressed (indum Dialium buttr 386535); twigs rather slender, grey to dark brown, lenticellate, young parts hairy.
Leaves imparipinnate, including petiole (7-)10-15(-20) cm long; petiolules (3-)4-6(-10) mm long, late glabrescent. (indum Dialium C ToS 35 )Leaflets (5-)7-9(-11), ovate-oblong or ovate-lanceolate to elliptic, (4-)6-10(-11) by (2.5-)3-5(-7) cm, (stiff) coriaceous; apex (long) acuminate to cuspidate, or obtuse to rounded; base rounded to cuneate; surfaces usually concolorous, glabrous above, glabrous to late glabrescent beneath; nerves 8-10(-14) pairs, nervation fine, distinct beneath.
Inflorescence : Panicles terminal, lower primary branches usually subtended by leaves or in fascicles axillary to fallen leaves, rachis 10-20 cm long; pedicels 2-6 mm.
Flowers white. Sepals 5, ovate-oblong to elliptic, up to 5 by 2.5 mm, minutely hairy inside. Stamens 2; filaments up to 1.5 mm long; anthers oblongish, 3.5-4.5(-5) mm long, usually opening before anthesis, connective sparsely hairy on both sides. Ovary sessile, up to 2 mm long, white hairy; style short, straight to slightly recurved at top.
Fruits globose to ovoid, sometimes slightly compressed, 1.5-2(-2.5) by 1-1.5 cm; exocarp brittle, hairy but not velvety (indum Dialium C ToS 35 ).
Seeds squarish to reniform, 7-12 by 5 mm, testa light to dark brown, shiny.
Distribution
Southernmost Thailand; Malesia : Western part.
Note
Two varieties can be recognized and identified fairly accurately. There are, however, intermediates.
Key to the varieties
a. Leaflets ovate-oblong to ovate-lanceolate, subcoriaceous, apex usually ong acuminate to cuspidate, nerves and reticulations distinct but slighly raised
Dialium indum indum
b. Leaflets broadly elliptic, sometimes roundish or broadly lanceolate, stiff coriaceous, apex abtuse to abruptly acuminate, nerves and reticulations prominently raised beneath Dialium indum bursa
a. Dialium indum Linnaeus var. indum
Leaves: Leaflets ovate-oblong to ovate-lanceolate, subcoriaceous, apex usually ong acuminate to cuspidate, nerves and reticulations distinct but slighly raised.
Distribution
Thailand, southern part; Malesia: Sumatra, Peninsular Malaysia, Borneo, Java.
Habitat
Low, well-drained flat country and hills, sometimes in swampy areas including peat swamp (Whitmore, 1972: 260), up to c. 1150 m altitude.
Ecology
Flowering throughout the year, peaks from February to June; fruiting peaks in May, August, and October.
Note
1. Dialium cochinchinense Pierre, a continental species, was recorded as cultivated in some villages in Peninsular Malaysia (Whitmore, 1972), but Rojo (1996: 612) did not come across any material.
2. Merrill (1917: 257) interpreted Tamarindus altera Rumphius (Herb. Amboin. 2 (1741) 93) as the present species.
b. Dialium indum Linnaeus var. bursa (de Wit) Rojo
Leaves: Leaflets broadly elliptic, sometimes roundish or broadly lanceolate, stiff coriaceous, apex obtuse to abruptly acuminate, nerves and reticulations prominently raised beneath.
Distribution
Sumatra, Peninsular Malaysia, Singapore, Borneo.
Habitat & Ecology
As the other variety, but not reported from swampy areas.
Note
The type specimen of D. laurinum (= Dialium indum ) is intermediate between the two varieties.