that the inflorescence appears headlike or spikelike; spikelets of few to many uni- 

 sexual flowers arranged spirally around the axis (rarely in definite rows) either 

 wholly staminate or pistillate or androgynous (with staminate flowers at top, pistil- 

 late below) or gynecandrous (reverse order); staminate flowers comprising merely 

 3 stamens (rarely 2) subtended by a scale; pistillate flowers merely a scale sub- 

 tending a "perigynium" that encloses an achene; perigynium an indehiscent bag 

 or envelop completely enclosing the achene (but not adherent to it) except at 

 the minute apical orifice through which the stigmas protrude at anthesis, falling 

 with the mature achene and thus a spurious outer portion of the fruit which is 

 unique to this genus. 



An enormous, technical genus occurring in moist temperate and moist cool 

 tropical regions. Carex is in dire need of critical taxonomic study bolstered by 

 cytology and by field and garden studies which might elucidate many of the 

 problems arising from hybridization or introgression. The keys and descriptions 

 can be used only when the material to be determined is complete with under- 

 ground parts and has fully mature achenes, the latter to be examined carefully at 

 a magnification of at least 15 diameters. 



Presumably caric-sedges provide some forage for stock. 



(Part of treatment adapted from F. J. Hermann "Manual of the Carices of the 

 Rocky Mountains and Colorado Basin." Agr. Handb. No. 374, Forest Service, 

 U.S. Dept. Agric. 1970). 



1. Achenes lenticular or plano-convex; stigmas 2 (2) 



1. Achenes trigonous; stigmas 3 (43) 



2(1). Terminal spike androgynous or gynecandrous (except C. Douglasii which 

 is dioecious); lateral spikes short and sessile (3) 



2. Terminal spike staminate, (rarely gynecandrous or androgynous); lateral 



spikes peduncled or elongate and sessile (35) 



3(2). Some or all spikes androgynous, not gynecandrous (or plants dioecious) 

 (4) 



3. Some (especially the terminal) or all spikes gynecandrous, with staminate 



flowers at base or scattered, not at apex (15) 



4(3). Rhizomes slender, elongating; culms mostly solitary; spikes (at least the 

 lower) distinct (5) 



4. Rhizomes short, not freely stoloniferous, with short internodes; culms or leafy 



tufts approximate (8) 



5(4). Plants dioecious or nearly so; perigynium beak nearly as long as the body 

 1. C. Douglasii. 



5. Plants not dioecious, the spikes mostly androgynous; perigynium beak shorter 



(6) 



6(5). Perigynia plump, unequally biconvex, rounded to the summit with fine 

 nerves on both surfaces, white-punctate 4. C. disperma. 



6. Perigynia broadly ovate to ovate-lanceolate, nerveless or nearly so, winged 



(7) 



7(6). Perigynia yellowish, brown to chestnut-brown, 1.7-2.7 mm. long, hyaline- 

 winged at the center; rootstock and lower sheaths light-brown 



2. C. simulata. 



7. Perigynia brownish-black, 3-4 mm. long, thin-coriaceous with sharp coriaceous 



margins; rootstocks blackish, fibrous 3. C. praegracilis. 



8(4). Spikes 2 to 15 in an ovoid, bractless head, 10-15 mm. long and 4-9 mm. 

 thick 6. C. cephalophora. 



8. Spikes numerous, in paniculate spikelike heads, usually 2 to several on each 



lateral branch (9) 



490 



