﻿604 Mackenzie: Notes on Carex 



two plants, and to justify Dewey in having proposed Carex tenera 

 as a distinct species. 



The real Carex straminea is a tall slender but rather stiff plant 

 of wet soil with stiff, little flexuous inflorescence ; the lower nodes 

 are exposed, and the sheaths are green-striate ventrally nearly 

 to the apex, the hyaline portion being short. The body of the 

 perigynium is strongly obovate and abruptly contracted into a 

 short beak less than half the length of the body; it is thin except 

 where distended by the achenes, and is strongly but finely five- to 

 seven-nerved ventrally over the stipitate achene. The scales are 

 not brownish tinged, but are hyaline with a conspicuous green 

 strip on each side of the mid vein. 



On the other hand, Carex tenera Dewey is usually a very slender 

 plant of dry soil with slender, flexuous inflorescence; the lower 

 nodes are not exposed and the sheaths are conspicuously hyaline 

 ventrally. The thick ovate perigynium tapers into the short beak, 

 and is less strongly three- to five-nerved ventrally over the sub- 

 stipitate achene. The scales are reddish brown tinged and lack 

 the conspicuous green strip on each side of the midvein. 



After separating these two plants a third element still re- 

 mained in the aggregate which had been referred to Carex straminea. 

 This has the nodes and sheaths as in Carex tenera. The leaves, 

 however, are wider, and the plant is much less slender. The 

 inflorescence consists of from four to nine spikes, which are nor- 

 mally strongly clavate at the base and not rounded as in theother two 

 species. The body of the perigynium is suborbicular or orbicular 

 and contracted into a beak half the length of the body, which is thick 

 and but faintly three- to five-nerved ventrally. The scales are more 

 or less strongly reddish-brown tinged. This plant is an exact match 

 for Carex festucacea Schkuhr (Riedgr. Nachtr. 23./. i/j. 1806), 

 and should take that name. 



The plant which has of late years been treated as Carex 

 festucacea and as Carex festucacea var. brevior (Dewey) Fernald 

 commonly has three to six little separated spikes rounded at the 

 base, but occasionally has more numerous and more separated 

 spikes which are then apt to be more staminate and hence more 

 clavate at the base. It is well distinguished from the species above 

 described by the perigynium exceeding 4 mm. in length, while the 



