CYPERACEAE (SEDGE FAMILY) 89 



numerous, bright white, 25-30 mm. long: achenes obovoid, obtuse, light 

 brown. In cold bogs; from Colorado to Canada and east to the Atlantic 

 States. 



3. Eriophorum gracile Koch, Roth, Cat. Bot. 2: 259. 1800. Culms slender, 

 2-4 dm. high, somewhat triangular: leaves slender, channeled-triangular, 

 rough on the angles: involucre short and scale-like, mostly 1-leaved: peduncles 

 rough or roughish-pubescent: spikelets 3-7, small, when mature the copious 

 white wool 12-15 mm. long: scales light brown, 3-nerved: achene linear- 

 oblong. Cold bogs; across the continent through the northern tier of States. 



5. HEMICARPHA Xees. 



Spikelet, flowers, etc., as in Scirpus except that there is a minute translucent 

 scale (readily overlooked) between the flower and the axis of the spikelet. 

 Stamen only one. Styles 2-cleft. Bristles or other perianth none. 



1. Hemicarpha aristulata (Coville) A. Xels. Bull. Torr. Bot. Club 29: 460. 

 1902. Annual, glabrous, culms few to several, erect, 8-15 cm. high, filiform 

 or capillary, exceeding the capillary leaves: involucral leaves 2-3, unequal, 

 5-20 mm. long: spikes 2 (sometimes only 1), ovoid, 3-5 mm. long: scales 

 rhombic, acuminate, the body nearly 1 mm. long, scarious-margined, some 

 of the margins turning brown, with a green midrib and inconspicuous nerves; 

 the acumination green, subulate, somewhat spreading, nearly as long as the 

 body of the scale or in the lower ones longer: sepal large, as long as the ovule, 

 obtuse or even with a truncate or toothed apex: filament barely exceeding the 

 ovule: style short, its branches inconspicuously if at all barbellulate: achene 

 obovoid, shorter than the body of the scale. Rare; moist sandy canons: 

 eastern part of our range, to Kansas and Texas. 



6. ELYNA Shrad. 



Perennial herbs with filiform leaves, radical or sheathing the stems at base. 

 Lowst glume inclosing an ovary with a long trifid style: the next one, or 

 rarely the next two, inclosing 3 stamens; often a rudimentary glume or awn 

 terminating the rachis; occasionally only one glume to a spikelet. 



1. Elyna Bellardii (All.) Koch, Linnaea Jl: GIG. 184S. Stems caespitose, 

 1-3 dm. high, striate-angled: leaves shorter than the stem: spikelets few, 

 small, and brown, in a somewhat clavate spike 20-25 mm. long. Kobresia 

 scirpina. The Colorado mountains. 



7. CAREX L.* SEDGE 



Perennial grass-like herbs, with 3- ranked leaves, mostly triangular culms, 

 and spikes in the axils or exserted from the sheaths of leaf-like or scale-like 

 bracts. Flowers in spikes, imperfect, the staminate and pistillate in different 

 parts of the same spike (spike androgynous), or in separate spikes on the same 

 culm (plant monoecious), or rarely on entirely distinct plarxts (plants dioecious). 

 Staminate flower composed of three stamens borne beneath a bract or scale. 

 Pistillate flower composed of a single pistil bearing 2 or 3 exserted styles, form- 

 ing in fruit a lenticular or triangular achenium which is inclosed in a more or 

 less inflated sac (pcrignnium) borne in the axil of a scale. 



Theoretically each flower is entirely destitute of floral envelopes, and borne 

 on a branch which springs from the axil of a scarious bract (the scale of the 

 following descriptions), the inclosing perigynium of the fertile flowers answer- 

 ing to one (or two) connate bractlet. In the subgenus Vignea of the present 



* The treatment of this genus remains essentially unchanged. As prepared for the 

 original Manual by Dr. L. H. Bailey, both the keys and the full diagnoses have proven 

 unusually satisfactory. Relatively few new species have been described in the meantime. 

 Some of these have been inserted and some of the seemingly extralimital ones have been 

 excluded. Changes in nomenclature are of course noted. Though the treatment is not 

 quite in harmony with the rest of this volume, it seems well to retain both the artificial and 

 the natura. keys. 



