34 BULLETIN 545, U. S. DEPARTMENT OF AGRICULTURE. 



seeds are found about August 20, and by the end of the first week in 

 September the whole seed crop has ripened. Data on the vitality 

 of the seeds were obtained only in 1909, when an average from three 

 tests gave 27.5 per cent germination. 



As its common name implies, sheep sedge is a highly relished 

 sheep forage. The leaves are tender and juicy throughout the sum- 

 mer, and the plant seems to be consumed with about the same eager- 

 ness at all times during the growing season. Horses, too, graze this 

 sedge with unusual eagerness, consuming flower stalks with the same 

 avidity as the leaf blades. Since sheep sedge is restricted to moist 

 habitats it is, of course, not very abundant, but in favorable situa- 

 tions it holds its own remarkably well, and it is not uncommon to 

 find it predominating over other sedges and more fastidious species 

 almost to their entire exclusion. 



Three other species, usually called marsh or water sedges, C. /es- 

 tiva, C. vulgaris bracteosa, and C. tolmiei subsessilis, are, on account 

 of their general appearance, forage value, and distribution, often con- 

 fused with sheep sedge. Of these, Carex j estiva resembles it most, 

 but differs in many minute characters (compare Plates XXVIII and 

 XXIX). The leaves of Carex f estiva are much broader and coarser, 

 and are rough on the edge, and the color of the plant is fight green. 

 The other two species, C. tolmiei subsessilis and C. vulgaris bracteosa 

 (Plates XXX and XXXI) have much more elongated spikes, of a 

 brown-black color, which alone should eliminate confusion. The 

 latter attains about twice the height of the former, and its culms are 

 more acutely angular. The forage value of all three species is prac- 

 tically the same, though C. vulgaris bracteosa is relatively less abund- 

 ant than the other two. C. tolmiei subsessilis remains palatable to 

 stock for a longer period than either of the others, but is more abund- 

 ant in the alpine or upper subalpine regions, and therefore matures 

 later, being of little importance as forage when the other species are 

 of highest value. 



Elk Grass. 



(Carex geyeri.) 



Of the dry-land sedges, elk grass is by far the most abundant. It 

 occurs in the Canadian and Hudsonian zones, often as the predomi- 

 nating species on exposed hillsides, and is among the earliest of the 

 herbs to send forth its leaf blades. Many hillsides have been almost 

 wholly vegetated by this species. 



Since elk grass produces new plants by stolons the growth is dense 

 and segments of a tuft are almost inseparable (Plate XXXII). The 

 slender, angled, rough culms, about 1 foot high, exceed but slightly 

 the harsh and rough-edged leaf blades. The spikes are slender, 

 borne at the summit of the culm, the staminate flowers usually 

 appearing above, and the pistillate (1 or 2 in number) below. 



