﻿On the characters and relationships of the genus IVIonopteryx 

 Spruce* 



The name Monopteryx was applied by Spruce to a papiliona- 

 ceous tree of the upper Rio Negro, in the forest region along the 

 boundary between Brazil and Venezuela. The name evidently 

 refers to the broadly developed upper pair of calyx teeth, which 

 completely enclose the floral bud and are conspicuous in the open 

 flower. In the notes on Spruce's travels, edited by the late 

 Alfred Russell Wallace, there are two references to this genus: 

 The first, accompanied by a well-drawn sketch, gives the size of 

 M. angustifolia Spruce and describes its strongly developed 

 buttresses, for which the native name "sapopema," i. e. flat root, 

 is proposed ;t the second assigns the other species, M. Uaucu Spruce, 

 to a place among the oil-yielding trees of Equatorial America. 



The first diagnosis of the genus, accompanied by description 

 of the two species, was given by Bentham in Martins* Flora 



The main generic characters were found in the short, sub- 

 bipartite calyx, with large upper lip formed by the union of the 

 two anterior lobes, and in the almost obsolete lower lip, entire or 

 obscurely tridentate, and exterior in the bud. Furthermore the 

 petals were stated to be sessile and almost equal in length to the 

 calyx, and the ten stamens to be free, with basifixed anthers. 

 The stipitate ovary, surmounted by a short style, was described 

 as uniovulate and the ovule as anatropous. Bentham supposed 

 that the unknown legume was drupaceous, because the other 

 affinities were with Dipteryx, notwithstanding which he placed 

 the genus among the Sophoreae. 



* Published by permission of the Secretary of Agriculture. 



t Notes of a Botanist on the Amazon & Andes i: 20-23; 335. /• 29; 480 



