Mackenzie: Notes on Carex 267 



Carex scirpoidea ; and two others — Carex scahriuscida and Carex 

 scirpiformis — are here proposed as new. 



In addition to valuable characters derived from the shape and 

 color of the perigynium and its pubescence or relative lack of 

 pubescence, the chief points connected with the inflorescence to 

 be noticed are the shape, relative length, and pubescence of the 

 scales. The width of the leaf-blades and the relative stoutness 

 of the culms, although at times relied on, are too variable to be of 

 real service, and while the western allies of C scirpoidea as a 

 whole seem much more inclined to grow in dense mats and to 

 have shorter dense rootstocks than that species I am not able to 

 judge from herbarium material alone whether this character can 

 be relied on. 



However, there is another character which Mr. Holm has used 

 in other groups of Carex and seems to be constant and of value in 

 the present group. That is, in some of the species the lower culm- 

 leaves are reduced to bladeless sheaths, thus leaving in the present 

 group but few (usually 3-5) well-developed leaves to a culm ; and 

 Ml other species the lower culm-leaves develop blades, thus giving 

 in the present group many (usually 6-10) well-developed leaves to 

 a culm. The former species are referred to as aphyllopodic ; the 

 ktter as phyllopodic. One of the best marks of distinction of 

 Carex pseudoscirpoidca is that it is phyllopodic, and this is also true 

 of the very local Carex gigas and Carex scahriuscida. On the 

 other hand the other three species are aphyllopodic. 



The following key will serve to distinguish the species and to 



P 



contrast their more evident points of difference : 



e ngynium sparsely pubescent towards apex only, dark brown- 

 ish-black. 



p engynium-body broadly oval, 3 mm. long, very abruptly 

 beaked. 



* e rigynium-body lanceolate, 4 mm. long, tapering into the 

 beak. 



eri gvnium densely pubescent to hirsute, lighter in color (or dark 

 at apex only). 



C gigas. 



C. scabriuscula. 



^rigynium lanceolate, rlattish, 4 mm. long. G stevochlaena. 



Per igynium broader, triangular, 3 mm. long or less. 



Culms aphyllopodic, the culm-leaves usually 3-5 ; scales 



shorter than perigynia. 

 Scales very minutely hyaline-margined ; perigynium 



whitish-pubescent. C - scirpoidea. 



