IROKO 



a height of as much as 150 feet. When very large it is gener- 

 ally hollow " (8). 



Authorities. Laslett (4), p. 275. Kew Guide (57), pp. 43, 38. 

 Miers (76). McTurk (78), No. 55. Holtzapffel (48), p. 94. 



Colour. Dark brown or dark reddish-brown streaked with 

 white or brown lines. Heart-wood sharply defined from the 

 yellowish or light brown sap-wood. 



Anatomical Characters. Transverse section: — 



Pores. Very prominent, giving the wood a " caney appearance" 

 (60) : size 2, little variation : evenly distributed over the whole 

 surface : few, 17-40 per sq. mm. : in groups of 1-6 pores but 

 mostly in threes, irregularly or radially subdivided : groups en- 

 closed in patches of soft-tissue which connect two or three of them 

 together : occasionally contain resin or gum. 



Rays. Need lens, size 5, uniform : equidistant, about the width 

 of a large pore apart, weak but scarcely avoiding them : numer- 

 ous, 5-7 per mm. : denser than the ground and of nearly the same 

 colour as the soft-tissue. 



Soft-tissue. Prominent : abundant in broad patches imbedding 

 and connecting the pores in an oblique or concentrically- 

 waved fashion. 



Pith. ? 



Radial Section. Considerably lighter in shade than the Trans. 

 Pores very prominent, light brown when bordered by soft- tissue 

 or chalky when filled with Apatite. Soft-tissue readily visible 

 as hoary borders to the pores but scarcely prominent. 



Tangential Section. The pores give the wood the appearance 

 of that of a Palm, being very prominent. Rays minute brown, 

 spindle-shaped lines about o - 5 mm. high. Soft-tissue the chief 

 feature, affording much contrast of colour and occupying at least 

 half the surface of this section. 



Type specimens from a log sent by the Government of British 

 Guiana to the Colonial and Indian Exhibition. 



No. 82. IROKO. Sp. unknown (see below) 

 Plate VI. Fig. 53. 



Natural Order. Leguminoseae. 



Source of Supply. West Coast of Africa : Lagos. 



Physical Characters, etc. Recorded dry-weight 39I lbs. per 

 cu. ft. Hardness Grade 6, compare Oak. Cleaves very easily. 

 Smell none, but the sawdust is very irritating to the nostrils. 

 Taste extremely vapid. Burns badly : supports a flame with 

 difficulty : embers glow in still air : much snow-white ash : no 

 resin or gum expelled by heat : no smell. Solution faint, clear 

 yellow. 



95 



