Saurauia aspera differs from many of the other Oaxa- 
can species of the genus in exhibiting a definite predilec- 
tion for sunny exposures. Although it is found to some 
extent in the forests, the tree is most abundant and ap- 
parently thrives better and grows larger when exposed 
to direct sunlight. It is one of the most characteristic 
of the heliophiles of the region and is usually seen in as- 
sociation with the orchidaceous E/pidendrum radicans 
Pavon ex Lindl. and Sobralia macrantha Lindl., the gen- 
tianaceous Chelonanthus alatus (Aubl.) Pulle and Lisi- 
anthus nigrescens Schlecht. & Cham., and other notable 
sun-lovers. 
The size of Sawrauia aspera is variable. The collection 
which is cited above (consisting of more than 100 speci- 
mens and 100 wood samples) was made from a small tree 
growing ina sunny field. The tree is only about twenty 
or twenty-five feet tall, but its branches are very wide- 
spreading. Che trunk measures ten inches in diameter 
one foot from the ground. The bark is soft, light greyish- 
brown. The wood is soft, white and coarse. This species 
is easily recognized by the extremely wide-spreading 
branches and the large number of showy inflorescences 
which bear a profusion of conspicuous, sweet-scented, 
white flowers. 
Misinterpretation of the data supplied on the labels of 
some of the older collections led Busealioni, who mono- 
graphed the American species of Saurauia (Malpighia 
27 (1916) 297), to present a very confused picture of the 
distribution of Saurauia aspera. In view of this, a few 
facts concerning the distribution of Sawrauia aspera and 
its botanical history may be of interest. Sawrauia aspera 
is apparently endemic to the northeastern part of the 
state of Oaxaca and the adjacent border of Vera Cruz. 
In northeastern Oaxaca, it is abundant in the Districts 
of Choapam, Villa Alta, [xtlin, Cuicatlin, and Teotitlan. 
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