Volume 13 > Part 1 > Year 2015 > Page 50 > Salicaceae > Osmelia

Osmelia maingayi Kingwfo-0000895420

J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 67: 19. 1898; Sleumer, Fl. Males., Ser. I, Spermat. 5: 78. 1954. Fig. 10; Plate V: 5.

Accepted Name : This is currently accepted.

Description : Tree to 20 m, most commonly less than 10 m. Stipules linear, to 6 mm long, caducous. Leaves with petiole to 1.8 cm long, densely hairy; blade elliptic, to 25 by 8 cm, base cuneate to rounded, often slightly asymmetric, margin with scattered minute glandular teeth but appearing entire, apex acuminate; up to 10 pairs of lateral veins, lower surface with rather dense spreading hairs throughout, upper surface with dense hairs along midrib, less dense on main lateral veins and rare elsewhere. Inflorescence of panicles in leaf axils or in leafless axils on old branches; the main axis to 40 cm long, secondary axes few to several, up to 15 cm long. Male flowers on densely hairy pedicels to 2 mm long, bracts subtending pedicels similarly hairy, the outer one narrowly triangular, to 1 mm long, the inner one much broader and approaching cupular, to 1 mm long; sepals suborbicular, to 2 mm long, outer surface with appressed hairs, inner surface glabrous; stamens to 3 mm long, exceeding sepals, filaments with some hairs; disc lobes to 1 mm long, densely hairy; rudimentary ovary densely hairy. Female flowers similar to male flowers, differing by stamen filaments shorter than petals and anthers sterile, ovary with ovules and prominent stigmas. Fruit ellipsoid, to 2 cm long, densely hairy, styles and stigmas persistent. Seeds ellipsoid to 8 mm long.

Thailand : PENINSULAR: Phatthalung, Trang, Songkhla, Narathiwat.

Distribution : Malay Peninsula (type), Sumatra, Borneo.

Ecology : In evergreen forests, at low altitudes.

Vernacular : Nguang chang (งวงช้าง)(Trang).

Notes: The hairs of all parts are yellowish on dried herbarium specimens, but described as greyish on fresh fruits. Sleumer states that the aril is red or yellow, and Maxwell describes it as orange on the immature seeds of one of his collections.

In Flora Malesiana (1954) Sleumer’s key separated Osmelia maingayi from O. philippina (Turcz.) Benth. by O. maingayi having ‘leaves usually olivaceous-tomentose beneath, very rarely ± glabrescent’, whilst O. philippina has ‘leaves usually glabrous, rarely and apparently not persistently pubescent on midrib and nerves beneath.’ Following the description of O. maingayi Sleumer noted: ‘As more material is coming in, the variation of both O. maingayi and O. philippina seems to increase, and it is quite possible that in future they cannot be kept separate,’ If they are the same, the taxon would be O. philippina, the older name.

The Sri Lankan species (Osmelia gardneri Thwaites) is described as having hermaphroditic flowers, whereas the Malesian species are described as dioecious. All the specimens seen appear to be restricted to either always male or always female flowers in any one collection, but the possibility of hermaphroditic flowers can’t be ruled out.