﻿Vol. 25 



No. 10 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



NOVEMBER 1898 



Revision of the Genus Triplasis, 



By Geo. V. Nash. 



This group of plants has been frequently considered a part of 

 the genus Triodia, founded by Robert Brown on a number of 

 Australian grasses which bear little more than a superficial resem- 

 blance to our plants. Hackel * so considered the group, but 

 Bentham & Hooker f adopted the views of Beauvois and gave to 

 it the dignity of generic rank. It has seemed to us for some time 

 that the genus Triodia embraced too many forms and that it 

 would be much more satisfactory to divide it into several 

 smaller groups. Triplasis approaches most closely to those plants 

 that have been referred to Triodia under the specific names 

 of avenacea, pulchdla, Nealleyi, etc. The flowering scales are 

 deeply 2-lobed as they are in those plants, but the internodes of 

 the rachilla of the spikelet in Triplasis are much elongated and 

 the callus is very long, sometimes two thirds as long as the inter- 

 nodes, and attached to the rachilla by a long oblique angle. The 

 callus being densely pilose on the free side gives the rachilla inter- 

 nodes the appearance of being pilose on one side for a part of their 

 length. This long and manifest callus with its very evident 

 oblique attachment is a character not known to us to occur m 

 any other of the many forms that have been referred from time 

 to time to Triodia. The conclusions of Beauvois certainly seem 

 tenable and better serve the end of systematic botany than does 



* Engl. & Prantl, Nat. Pflanzenfam. 2 2 : 68. 1S87. 

 fGen. Plant. 3 2 : 1176. 1883. 



[Issued 7 November.] ( 561 ) 



