94 CYPERACEAE (SEDGE FAMILY) 



longer than the long-pointed and mostly channeled leaves: spike linear or 

 clavate, 1-3 cm. long: perigynium upright, plano-convex, obovate or elliptic, 

 firm in texture, dull, very lightly nerved, abruptly contracted into a short and 

 stout truncate beak, hidden by the amplectant and very laroad dark scale. 

 Colorado and far northward. 



11. Carex obtusata Lilj. Kongl. Acad. Hand. 69. t. 4. 1793. Very ex- 

 tensively creeping by long and slender brownish rootstocks: culms 5-15 cm. 

 high, longer than the flat and long-pointed leaves: spike at maturity ovate or 

 narrowly ovoid, 12 mm. or less long, the pistillate flowers 4-10: perigynium at 

 first pale, brownish at the top, when mature spreading and becoming brown or 

 dark brown-purple, glossy, very horny in texture, turgid-ovate, stipitate, con- 

 tracted into a stout obliquely-cut and conspicuously white-hyaline beak, 

 longer and broader than the membranaceous, acute, and often deciduous scale : 

 achenium short and broadly triangular. South Park, Colorado, to Montana, 

 westward and northward. 



5. Spikes 2 or more (1 in No. 12), more or less peduncled: staminate spike 

 one in our species: pistillate spikes mostly compactly flowered and cylin- 

 drical, erect: bracts leafy, sheathing or sheathless: perigynium firm in tex- 

 ture, smooth, slightly inflated, very shortly and stoutly beaked or sometimes 

 beakless, conspicuously nerved. BRACHYRHYNCHAE. Slender, not very 

 leafy species. 



* Spike one, staminate above: perigynium beakless. POLYTRICHOIDEAE 



Tuckm. 



12. Carex leptalea Wahl. Kongl. Vet. Acad. Handl. II. 24: 139. 1803. 

 Caespitose : culms many, almost capillary, usually longer than the very narrow 

 leaves: staminate flowers very few: perigynia 2-8, alternate and appressed, 

 green, triangular below, flattened towards the top, blunt or emarginate at the 

 apex, much longer than the ovate acute scale: stigmas rarely 2. C. poly- 

 trichoides. Low ground, Colorado and northward. 



* * Staminate spike in our species sessile or short-stalked: pistillate spikes 

 short: perigynium obtuse or short-beaked, straight at the apex, longer than 

 the white or tawny acute scale. PALLESCENTES Fries. 



13. Carex abbreviata Prescott, Boott, Trans. Linn. Soc. 20: 141. 1846. 

 Culms 2-4 dm. high, sharply angled, longer than the hairy leaves: pistillate 

 spikes 1-3, roundish, approximate, almost sessile: perigynium round-obovate, 

 sunken at the top, very abruptly tipped with a short stout hyaline-margined 

 beak: bracts short, about the length of the culm, sheathless. C. Torreyi. 

 Colorado and northward into British America. 



* * * Staminate spike usually long-peduncled: pistillate spikes scattered, all 



(at least the lower) on exserted stalks: bracts shorter than the culm (longer 

 in No. 14), sheathing: perigynium glaucous-green before maturity, becom- 

 ing pale or yellow, the apex oblique or bent and short-beaked (or nearly beak- 

 less in No. 14). PANICEAE Tuckm. 



14. Carex aurea Nutt. Gen. 2: 205. 1818. Stolonif erous : culm 4-25 cm. 

 high, slender, sharply angled, longer or shorter than the flat and narrow 

 glaucous leaves: bracts leaf -like, the lower much exceeding the culm: spikes 

 3-6, the staminate often nearly sessile, the pistillate loosely flowered, the lower 

 remote, often on radical peduncles: scales colored on the margins, ovate, 

 shorter 'than the turgid, globose or pear-shaped, bright yel)ow or straw- 

 colored and wholly obtuse or slightly pointed perigynium : stigmas commonly 

 two. Common throughout on moist grassy hillsides and low mountains. A 

 delicate and pretty species, readily distinguished when mature by its bright 

 colored, often almost fleshy perigynia. The staminate spike is occasionally 

 pistillate at the apex. 



6. Staminate spike mostly solitary and peduncled, pistillate spikes several 

 or many, more or less loosely flowered, all or the lower on filiform weak or 



