CYPERACEAE 17 



POALES. (GRAMINALES.) 



Leaves 3 ranked, with closed sheaths; stems usually solid; fruit an 

 achene. 1. Cyperaceae. 



Leaves 2 ranked, with open sheaths; stems usually hollow; fruit a 

 cariopsis. 2. Poaceae. 



1. CYPERACEAE. 



The sedges. 



The sedges are closely related to the grasses w^hich they resemble 

 so much that they are often confused with them. Most sedges prefer 

 a moist soil but a few are xerophytic. In low meadows they often 

 furnish a large part of the forage, but are inferior to the true grasses 

 for hay and pasture. Some sedges are called "wire-grass" by farmers. 



Flowers of the spikelets all, or at least one of them perfect, achene 

 not in a closed perigynium. 

 Perianth of scale-like sepals. 



Sepals 3 petal-like. 1. Fuirena. 



Sepals single, hyaline, 2. Hemicarpha. 



Perianth of bristles or wanting; not of scales. 

 Scales of the spikelets spirally imbricated. 

 Base of style persisting as a tubercle on the achene, 



Spikelets solitary, 3. Eleocharis. 



Spikelets in a terminal umbel, 4. Stenophyllus. 



Base of the style not persistent as a tubercle on the achene. 



Style swollen at the base; perianth none. 5. Fimbristylis. 



Style not swollen at the base; perianth usually present. 



Bristles, if present, not long and hairlike. 6. Scripus. 



Bristles long, hairlike. 7. Eriophorum. 



Scales of spikelets in 2 ranks. 



Inflorescence axillary, perianth of bristles. 8. Dulichium. 



Inflorescence terminal, perianth wanting. 9. Cyperus. 



Flowers monoecious or dioecious; achene in a perigynium. 10. Carex 



1. Fuirena. 182. 



Perianth-scales awned at the tip. 1. F. squarrosa. 



Perianth-scales awned below the tip. 2. F. simplex. 



1. Fuirena squarrosa Michx. 

 Nebraska, according to Britton's Manual. 



2. Fuirena simplex Vahl. 



In wet soil mostly along streams. Kearney; Minden. 



2. Hemicarpha. 183. 



Scales brown, with short spreading or recurved tips. 1. H. michantha. 

 Scales pale with squarrose awns equal to their own length. 



1. H. micrantha van. aristulata^ 



1. Hemicarpha micrantha (Vahl.) Pax. 



In moist soil over most of the state; frequent on sand-bars. Atkin- 

 son; Cherry County; Fremont; Ewing; Long Pine; Minden. 

 la. Hemicarpha micrantha aristulata Coville. 

 Long Pine. 



