cook: tribroma, a new genus of trees 289 



Low, shade-tolerant trees of tropical undergrowth, the lateral branches 

 formed in terminal clusters of 5, rarely 4 or 6; leaves elliptrc-obovate, 

 narrowed toward the base, pinnately veined, naked on both surfaces, 

 the petioles and young shoots hirsute with stiff erect bristles; leaves of 

 lateral branches of the same form as those of the upright shoots, the 

 petioles somewhat shorter, but the pulvini distinct at each end; inflo- 

 rescences reduced to minute fleshy twigs, only the terminal joints 

 distinct and these shorter than the pedicels of the flowers, produced 

 from adventitious buds on old wood of the main trunk or the larger 

 branches, long after the leaves; flowers larger than in Tribroma, the 

 sepals and petals both conspicuous, light colored, widely expanded; 

 sepals narrow, tapering and reflexed; petals longer than the sepals, 

 strongly curved or folded in the bud, the basal hood with two strong 

 parallel ribs, the hmb longer than the hood and with a slender base 

 folded down around the end of the hood; staminodes slender, naked 

 and tapering above, laterally compressed below, with bands of long 

 hairs on the lateral faces; ovary rounded, covered with glandular 

 pubescence like the sepals and the pedicel; fruits obovate or fusiform, 

 with a thick fleshy rind, longitudinally ridged and furrowed, the sur- 

 face smooth or tuberculate. 



A more detailed account of the differences between the two trees, 

 with special reference to their habits of branching and their floral 

 biology, illustrated by photographs, is being offered for publication in 

 the Contributions from the United States National Herbarium. 



