94 CYPERACEAE (SEDGE FAMILY) 



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

 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 broad 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 homy 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. — Bkachybhynchae. Slender, not very 

 leafy species. 



* Spike one, staminate above: perigynium beakless. — Poltthichoideab 



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-peduruHed: 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 viaturity,^ becom- 

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

 less m No. 14). — Paniceab Tuckm. 



14. Carex aurea Nutt. Gen. 2: 205. 1818. Stoloniferous: 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 yellow 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.c 



