﻿Mackenzie: Notes on Carex 611 



and its numerous allies, so widely distributed especially in the 

 eastern part of North America. This, however, is only a tendency, 

 as a number of species of the C. festiva group, especially from Cali- 

 fornia, have an elongated inflorescence; while on the other hand 

 a number of species of the C. straminea group have a congested 

 inflorescence. 



Probably the best character to use to separate the two groups 

 is that in the C. festiva group the beak of the perigynium towards 

 the apex is slender and almost terete, and the margin for the 

 last one or two millimeters is smooth or very sparingly serrulate. 

 On the other hand in the C. straminea group the beak of the peri- 

 gynium is flat and serrulate-margined to the tip. 



For many years the name " Carex festiva Dewey" has been 

 applied to specimens from the western mountains, and a plant 

 especially common in Colorado and Wyoming has been taken to 

 be the typical form. In this plant, which is the C. festivella of 

 the present paper, the perigynium tapers into a dark slender 

 beak half the length of the much lighter colored body and con- 

 trasting strongly with it in color. In the genuine boreal plant 

 both body and beak are reddish tinged and the beak is only one 

 fourth or one fifth the length of the body. In both species the 

 extreme tip of the perigynium is hyaline. The Rocky Moun- 

 tain plant is striate-nerved on the inner face; the boreal plant is 

 essentially nerveless. 



In addition to those characters taken from the perigynium 

 it may be added that the boreal plant has reddish scales and the 

 Rocky Mountain plant dark colored scales. 



In the boreal plant the fertile culms develop several leaves 

 the first year, and at flowering time in the second year these 

 remain in a more or less dried-up condition at the base of the 

 culms. As a result of this manner of growth there are always 

 present numerous well-developed flowerless culms in a clump 

 consisting of the first year fertile shoots and the more leafy sterile 



In the Rocky Mountain plant the fertile culms normally develop 

 all their leaves and flower during one year, and in consequence 

 there are no old dried-up well-developed leaves towards the base 

 of the flowering culms. At flowering time the shoots for the 

 next year are very evident, but have no developed leaves. As 



