Leucostegane
Content
Description
Trees.
Leaves spiral, paripinnate, (1- or) 2-5- (or 6-)jugate; stipels very small.
Stipules intrapetiolar, persistent.
Inflorescences racemose, fascicled, on trunks or old branches, or in axils of fallen leaves; bracts and bracteoles small, persistent beyond anthesis or deciduous.
Flowers bisexual, zygomorphic, pedicels articulated above the two bracteoles.
Petals 2 (or 1) developed, lateral, much shorter or smaller than the calyx lobes, with or without reduced or rudimentary ones.
Stamens 2 fertile, opposite the petals; filaments filiform, dilated at basal parts; anthers ovoid or oblong, longitudinally dehiscing; staminodes 2 or 3.
Ovary with the stipe free from or adnate to the floral tube, oblong or elliptic, 2-5- (or more-)ovuled; style filiform; stigma capitel- late.
Seeds discoid or ellipsoid.
Distribution
Asia-Tropical: Borneo (Sarawak present); Malaya (Peninsular Malaysia present)
Malesia: Malay Peninsula and Borneo (Sarawak), 2 species.
Taxonomy
Some sterile specimens of Leucostegane may resemble Saraca. However, in the former the leaflets are sometimes stipellate and the stipules are intrapetiolar and persistent while in Saraca the leaflets are never stipellate and the stipules are axillary and usually caducous.
Flowering collections of Leucostegane can be distinguished easily from collections of Saraca by the presence of two petals, with or without reduced or rudimentary ones (against petals absent) and two fertile stamens (against usually 4-8).
The pollen grains of Leucostegane and Saraca are globose, tricolporate. However, the exine patterns in these two genera are quite different: conspicuously verrucate in the former and scabrate-punctate in the latter.