Triplochiton scleroxylon K. Schum.

Triplochiton scleroxylon K. M. Schumann

Standard trade name: Obeche, African whitewood

Local name: Wawa (Ghana)

A large tree up to 160 ft high and 10 ft or more in girth, bole straight and unbranched, up to 80 ft. Extensive, sharp buttresses extend as far as 25 ft up. The leaves are eaten by the African silkworm, Anaphe venata.

GENERAL DESCRIPTION.—Obeche, soft and light, has an average weight of about 24 lb/ft3 when seasoned and about 35 lb/ft3 green. Its color is nearly white or pale straw. There is no clear distinction between sapwood and heartwood, the sap-wood being about 3–4 in wide. The grain is typically interlocked and the texture moderately coarse.

SEASONING.—Obeche seasons very rapidly and well, with very little or no defects. British Forest Products Laboratory kiln schedule L is recommended (FPRL, 1956).

DURABILITY.—The timber is susceptible to attack by ambrosia and powder-post beetles. It is not durable. In preservative treatment the sapwood is permeable but the heartwood is resistant.

WORKING QUALITIES.—The wood works very easily with all hand and machine tools with little dulling effect on the cutting edges. The timber finishes well in most operations, taking nails and screws readily, although they do not hold well under certain circumstances. It requires grain filler in polishing.

USES.—Used for interior core of plywood, for crating and packing cases. It is also used for interiors of drawers and cupboards.

XYLEM ANATOMY.—Slight evidence of growth rings. Wood diffuse-porous, but looks slightly ring-porous in distribution. Vessels: solitary but with a few radial multiples of 2 or 3 pores; circular in outline, slightly angular, average pore diameter 126μm, range 110μm–150μm; average vessel element length 300μm, range 212μm–375μm; perforation plates exclusively simple; vessel element end wall inclination slightly oblique to transverse; intervascular pitting opposite, rather large. Imperforate tracheary elements: septate fiber tracheids, average length 1690μm, range 1225μm–2075μm; fibers with few simple pits on tangential Avails. Vascular rays: heterogeneous, mainly multiseriate, generally 7 cells wide, 34 cells high, but biseriate and uniseriate cells also present; fusiform rays up to 4 cells wide. Axial parenchyma: apotracheal, abundant. Biseriate and uniseriate also present; fusiform rays up to 5 cells wide.

Triplochiton scleroxylon is a tree of the genus Triplochiton of the family Malvaceae. The timber is known by the common names African whitewood, abachi, obeche (in Nigeria), wawa (in Ghana), ayous (in Cameroon) and sambawawa (in Ivory Coast). The tree is the official state tree of Ekiti State, Nigeria.