AFRICAN OAK 



No. 171. AFRICAN OAK. Oldfieldia africana. Bth. 



and Hook. 

 PLATE XII. FIG. 106. 



Natural Order. Euphorbiaceae. 



Alternative Name. African Teak. 



Sources of Supply. Tropical Africa. Sierra Leone (107). 



Physical Characters, etc. Recorded dry-weight 58^ to 68 Ibs. per 

 cu. ft. Hardness Grade, 2 compare Boxwood. Smell none. Taste 

 strong and nauseous. Burns well with a quiet, steady flame : 

 embers glow in still air : much ash. Solution brown : with 

 water it gives off a peculiar smell. 



Grain. Fine and open. Surface bright. 



Bark. ? 



Uses, etc. " For all strong work and one of the best woods of 

 Sierra Leone" (107). " Rated second class at Lloyd's" (60). Las- 

 lett gives useful mechanical tests. This is not the African Oak 

 commonly met with on the English market, which is Lophira 

 elata. No. 6. The specimen from which this description is made 

 is a piece sent me from Kew by the kindness of Sir Wm. Th. Dyer 

 and is, I believe, from a block supplied by Laslett himself. I 

 have never met with the wood elsewhere, and consider that it 

 should be more generally used. 



Authorities. Kew Guide (574). Laslett (60), p. 299. Scott- 

 Elliot and Raisin (107). 



Colour. Uniform dark brown. Sap-wood. ? 



Anatomical Characters. Transverse section : 



Pores. Prominent from their numbers and colour, size 3-4, 

 rather smaller in the outer side of the ring : uniformly distributed, 

 not numerous, about 40 per sq. mm. : a few subdivided to groups 

 of 3 or 4 but mostly single : oval : many contain a white deposit, 

 others red. 



Rays. Just visible, size 5-6, uniform : equidistant : weak, 

 avoiding the pores (wriggling, so to speak) : long : very numerous, 

 about 12 per mm. : lighter in colour than the ground : a pore- 

 width or less apart. 



Rings. Very clearly marked : contour slightly undulating : 

 boundary a zone of wood poor in pores, no distinct line. 



Soft-tissue. Narrowly and neatly encircling the pores : also 

 minute imperfect cross-bars (micro.), which in the later wood of 

 the ring are sometimes developed into, continuous, concentric 

 lines finer than the rays. 



Pith. ? 



Radial Section. Pores just visible with lens as empty, shining 

 grooves filled with white or red contents. Rays, imperceptible 

 from lack of contrast. Rings, scarcely indicated. 



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