2 BULLETIjST 1050, U. S. DEPAETMEXT OF AGRICULTURE. 



iised principally as acknowledged imitations of mahogany, but some- 

 times they are used in furniture sold as genuine mahogany. 



Of the woods mentioned in this bulletin, true mahogany, crabwood, 

 the Cedrelas, sapeli, and "African mahogany " come from trees which 

 are botanically of the mahogany family (Meliacese). They are uni- 

 fonnly distinguished from other woods herein described by the occur- 

 rence of a dark reddish-brown gum in the pores. This gum does not 

 completely fill the pores, but occurs as almost black masses here and 

 there. It is seen best with a magnifying glass on longitudinal sur- 

 faces, but in many specimens is visible without a lens. Of course, 

 woods of other families may have dark gum in the pores, but none 

 such are commonly substituted for mahogany.^ 



Key foe the Identification of Teue Mahogany and Mahoganylike Woods.' 



(Also read carefully the descriptions of these species in the following pages 

 and study the illustrations.) 



I. Wood light to dark reddish brown. 



A. Many pores contain more or less of a very dark reddish brown 

 gum visible on longitudinal and end surfaces. Otherwise the 

 pores are open, no tyloses being present. The gum is visible 

 without, but better with a hand lens. 



1. Growth rings sharply but not always conspicuously defined. 

 AA. Wood without characteristic odor. Growth rings de- 

 fined by distinct but not always conspicuous lines of 

 soft tissue 3*2 to V2 inch apart. Pores in each growth 

 ring almost uniform in size. 



a. Lines of soft tissue light-colored and conspicuous. 



Kays on a freshly cut or split radial surface not 

 much darker than adjacent fibers. Tangential sur- 

 face occasionally but not always figured with very 

 fine bands which run across the grain, due to the 

 rays being in stories. Wood highly variable in 

 weight and light to dark reddish brown in color. 

 True mahogany (Stmetenia spp.). 



b. Lines of soft tissue mostly dark, not conspicuous. 



Rays on a freshly cut or split radial surface consid- 

 erably darker and more reddish than adjacent 

 fibers and usually with a slight purplish tinge. 

 Rays not in stories. Wood moderately hard. Color 

 more of a plain brown than in true mahogany. 

 Crabwood {Carapa guianensis). 



1 To one familiar with the examination of wood sections under a high-power microscope, 

 the exceedingly fine pits (as small as in birch) between adjacent vessels and also the 

 septate wood fibers found in Sicietenict', Carapa, Entandropliragma, and Khaya offer an 

 additional means of distinguishing these members of the mahogany family from others 

 not of the same family. In Cedrela the pits are larger, but also very numerous, and the 

 Avood fibers are sparingly septate. Bosicellia (family Burseracea;) also has septate wood 

 fibers, but the pits in the vessel walls are comparatively large. 



-Unless otherwise directed all observations as to structure should be made on the end 

 surface cut smoothly with a very sharp Isnife, and all observations as to color should 

 be made on freshly cut longitudinal surfaces of the heartwood. 



