CYPERACEAE 51 



flowered, usually contiguous : perigynia 1'' long, round-ovate, hairy. — 

 Very common in dry woods and on the prairie. April- May. 



27. C. varia Muhl. Resembles the last but staminate spike only 'i"-\'^ 

 long, sessile : pistillate spikes 2-4 : perigynia oblong. — Infrequent in dry 

 rocky woods throughout the northern part. April-May. 



28. C. umbellata Schk. Densely tufted, leaves \"-1" wide, often 1° 

 long : spikes on scapes 1^-2^ long, numerous, hidden among the leaves 

 or on short culms : pistillate spikes filiform-stalked or sessile at the base 

 of the solitary staminate spike, several-flowered, 2'^-4'^ long : perigynia 

 V long, minutely hairy. — In dry soil. Common near Dodson ; also found 

 north of Lee's Summit. April-May. 



29. C. pubescens Muhl. About \\° high, pubescent all over : stami- 

 nate spike sessile and inconspicuous : pistillate spikes 2-5, \"-\W long, 

 erect and nearly sessile: perigynia ovoid, 2^^ long, densely hairy. — In 

 rich woods near Sibley and Independence. May-July. 



30. C. Jamesii Schwein. 12' or less high : leaves \V' wide, much ex- 

 ceeding the culms : spikes small, the staminate portion slender and in- 

 conspicuous, with 2-4 pistillate flowers at base ; perigynia globular, pro- 

 longed into a rough, two-edged, stout beak : lower scales bract-like and 

 foliaceous. — Common in dark, rich woods throughout. May-June. 



31. C. conjuncta Boott. Culms weak, l°-3° high, sharply triangular : 

 leaves often \V' wide : head V-Z' long, the lower spikes separated : bracts 

 inconspicuous : perigynia \\" long, lance-ovate, tapering into a rough 

 beak, about the length of the cuspidate scale. — Not uncommon in moist 

 meadows and thickets in the northern part. May-June. 



32. C. stipata Muhl. Culms 2°-3° high : leaves 2''-4'' wide : head 

 1^-4' long, usually not branched, the spikes yellowish-brown and 

 crowded : perigynia lanceolate, 2^'' long, the beak longer than the body 

 and much exceeding the scale. — Frequent in moist meadows from Sheffield 

 and Adams to Sibley and Levasy. May-June. 



33. C. Crus-Corvi Shuttlw. Culms 2°-4° high : leaves b" or less 

 wide : head very compound, 4^-12' long : spikes yellowish-brown : peri- 

 gynia lanceolate, \" long, the beak more than thrice the length of the 

 body : scale one-fourth the length of the perigynia. — Locally common 

 around swamps at Sibley and Atherton. June-July. 



34. C. gravida Bailey. Culms 1°-3J° high : leaves l''-2'' wide, usu- 

 ally shorter than the culm : the globular spikes aggregated in a short 

 {V-\\' long) oblong head, somewhat interrupted: perigynia broadly 

 ovate, 1" long, polished and widely spreading when ripe.— Common in 

 dry soil, especially on dry prairies throughout the southern part. May- 

 June. 



Var. laxifolia Bailey. Leaves Z" wide : head dense, not interrupted. 

 — Prairies near Lee's Summit. 



35. C. vulpinoldea Michx. Culms often 3° high, exceeded by the 

 leaves: head V-h' long, usually interrupted, the numerous spikes 2'M'''' 



