Diplospora DC. (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Diplospora DC.

Family: Rubiaceae

• Diplospora kunstleri King & Gamble, synonym: Urophyllum potatorium King.

• Diplospora malaccensis Hook.f., synonym: Tricalysia malaccensis (Hook.f.) Merrill.

• D. kunstleri : Peninsular Malaysia: kahwah hutan.

• D. malaccensis : Peninsular Malaysia: gading-gading, kahwah hutan, uloh-uloh
• Thailand: yamkhwai (peninsular).

Diplospora comprises some 20 species. D. kunstleri is endemic to Peninsular Malaysia. D. malaccensis occurs in peninsular Thailand, Peninsular Malaysia, Sumatra and Borneo.

A hot decoction of the leaves of both species used to be drunk in Peninsular Malaysia as a substitute for coffee. The wood of D. malaccensis has proved suitable for use in "guillotine machines" (probably some cutting device), where it lasted three times as long as "chengal" ( Neobalanocarpus heimii (King) P. Ashton).

Leaves opposite, entire, coriaceous; stipules triangular. Flowers bisexual or male, small, in short axillary cymes or fascicles, 4-merous; calyx with short tube and triangular lobes; corolla trumpet-shaped, whitish, lobes contorted to the left in bud; disk annular; stamens 4, inserted on the corolla throat, exserted; ovary inferior, 2-locular with 1-3(-6) ovaries in each cell, stigma 2-lobed. Fruit a small, globose or ellipsoid berry, turning orange and red when mature. Seed not embedded in the placenta, angular, hemispherical, spherical or flattened.

• D. kunstleri : shrub or small tree up to 4 m tall; leaves oblanceolate or oblong, 15-18 cm × 4.5-6.5 cm, shortly acuminate, with 8-10 pairs of secondary veins; corolla with about 3 mm long tube and very short lobes; fruit ovoid, about 10 mm long.

• D. malaccensis : small to medium-sized tree up to 18 m tall with fairly straight bole and smooth to cracked or flaky, white to yellowish-brown, grey or black bark; leaves elliptical, 4-15 cm × 1-6.5 cm, shortly acuminate or acute, with 4-6(-7) pairs of secondary veins; corolla with about 2.5 mm long tube and c. 1.5 mm long lobes; fruit globose, about 17 mm in diameter.

The wood of D. malaccensis is apparently very hard. Heartwood pale yellow-brown with a slight pink tinge, not distinct from the sapwood; grain straight; texture fine and even. Growth rings visible to the naked eye; vessels very small to moderately small, mostly solitary but with some radial pairs; parenchyma moderately abundant, apotracheal diffuse, paratracheal confluent; rays very fine, 1-2-seriate; ripple marks absent. The wood does not develop surface checks when carefully seasoned. The genera Diplospora and Discospermum Dalz. are closely related, but the latter can be distinguished by its larger, drier fruits and the frequently well-developed placental outgrowths around the seeds. D. malaccensis most probably does not belong to Diplospora , but rather to a genus of the tribe Hypobathreae ; its proper generic position remains to be determined. D. kunstleri is found in montane forest at 1100-1400 m altitude. D. malaccensis occurs in lowland and montane forest up to 1500 m altitude.

5, 15, 23, 28, 55, 75.

M.S.M. Sosef