110 University of California Publications in Botany [VOL. 9 



shows material difference from the typical plant of the west and he 

 has therefore described it as S. rubrotinctus (Rhodora, vol. 2, p. 20, 

 1905). M. E. Jones 97 later reduced this species to a variety of S. 

 microcarpus. 



3. ERIOPHORUM 



1. Eriophorum gracile Roth., var. caurinum Fernald, Rhodora, 

 vol. 7, p. 67. 1905. 



Type locality. "Oregon, subalpine regions." 



Range. Oregon southward to Mt. Shasta and the northern Sierra 

 Nevada. 



Zone. Canadian. 



Specimens examined. Sierra County, Lemmon in 1874 ; Big Trees, 

 Hildebrand 2331. 



4. CAREX 



A.i Spikelets solitary and terminal. 



Female scales persistent, concealing the mature perigynia; leaves filiform- 

 involute or carinate. 



Stigmas 2 1. C. capitata 



Stigmas 3. 



Perigynia neither chartaceous nor inflated; spikes narrowly cylin- 

 drical 2. C. filifolia 



Perigynia chartaceous, inflated, and very thin; spikelets pyramidal. 



3. C. Breweri 



Female scales falling, exposing the maturing perigynia; leaves nearly 



flat 4. C. nigricans 



A. 2 Spikelets 2-many. 



B.i Stigmas 2; spikelets all or nearly all bisexual, or dioecious and sessile; 

 achene lenticular in cross-section; male flowers few and incon- 

 spicuous. 



Staminate flowers borne at top of the spikelets. 

 Plants with long creeping rhizomes. 



Perigynium with a short minute beak 5. C. simulata 



Perigynium long-beaked. 



Spikelets in a dense, broad, compact head; scales not at ajl or 



only narrowly hyaline-margined 6. C. vernacula 



Spikelets forming an oblong continuous spike; scales with broad 



hyaline margins 7. C. siccata 



Plants caespitose with scarcely spreading rootstocks. 



Ferrugineous scales of the spikelets scarious margined and with 



green midribs 8. C. Hoodii 



Scales of the spikelets not scarious margined. 



Acute scales of the spikelets reddish-yellow with straw-colored 



keels; culms weak, somewhat compressed 9. C. nervina 



Blunt scales of the spikelets brown; culms stiff, sharply angled 



and rough 10. C. Jonesii 



Staminate flowers borne at base of the spikelets. 



Perigynium not wing-margined (slightly winged at base in C. illota). 

 Spikelets few and rather loosely flowered. 



Scales green, acute, and marginless; spikelets remote; plant 



stoloniferous 11. C. tenella 



Scales reddish, blunt, and white margined; spikelets approxi- 

 mate; plant not stoloniferous 12. C. heleonastes 



