288 GRAMINE^). stipa. 



margins ; ligule very short, lacerate-fringed ; sheaths somewhat loose, the uppermost 

 much dilated, striate, smooth except the margins, which are mostly ciliate, especially 

 at the throat : panicle 12 to 16 inches long, at first spike-like and included for one- 

 third or one-half its length, at length exserted and loose, but narrow with erect 

 branches ; lower rays in pairs or threes, long and flower-bearing above, the upper in 

 fascicled clusters and flower-bearing to the base : spikelets short-pedicelled, pale- 

 greenish becoming purplish : glumes unequal, the 3-nerved lower about 8 lines, and 

 the 5-nerved upper 6 lines long, both acuminate and somewhat bristle-pointed, 

 slightly scabrous on the nerves : floret, including the brief curved callus and long 

 hairy crown, 5 lines long ; lower palet scarcely chartaceous, bifid with delicate hya- 

 line teeth less than a line long, clothed with silky shining hairs, those below about 

 a line long, the upper more numerous, forming a dense tufted corona 2 lines long ; 

 awn about an inch long, slender, bent mostly below the middle and minutely sca- 

 brous ; upper palet about half the length of the lower : stamens 3 ; anthers naked. 



Hills near Julian City, San Diego County (Bolander] ; near San Bernardino, Parry & Lemmon, 

 n. 422 (1876). The tallest and most robust of all North American Stipas ; when young, with the 

 panicle partly included, it appears somewhat like S. Stillmani, but it lacks the marked and 

 peculiar lustre of that species. Later the panicle is exserted, becoming wider and loose and taking 

 on a purplish tinge, .and the resemblance is no longer noticed. The remarkably long hairs upon 

 the floret have a peculiar silvery lustre ; when highly magnified each hair is seen to be flat and 

 spirally twisted. 



11. 8. viridula, Trin. Culms 1J to sometimes 5 feet high, with numerous 

 withered sheaths at base : leaves all involute-setaceous at apex, smooth or slightly 

 scabrous, pale green, the radical about one-third as long as the culm ; upper culm- 

 leaf 1 to 1 inches long ; ligule very short ; sheaths half the length of the internodes 

 or less : panicle 6 to 18 inches long, narrow, loose, the short erect rays in twos or 

 threes : spikelets 4 to 5 lines long, on shorter pedicels : glumes nearly equal, ovate, 

 bristle-pointed, the lower 5-, the upper 3-iierved, sometimes tinged with purple : 

 floret fusiform, about one-fourth shorter, the callus very short ; lower palet with 

 short scattered hairs which form a rather irregular crown and with 2 very minute 

 hyaline teeth ; upper palet more than half as long ; awn 1 to 1 J inches long, slender, 

 flexuose, usually twice bent, pubescent below and scabrous above, at length decidu- 

 ous : anthers naked. Act. Petrop. 1836, 39 ; Trin. & Rupr. Stipacese, 57 ; Watson, 

 Bot. King Exped. 380. S. parviflora, Nutt. Gen. i. 58, not Desf. S. spartea, 

 Hook. Fl. Bor.-Am. ii. 237, not Trin. 



In the Coast Ranges and Sierra Nevada, northward to Oregon, the upper Missouri (Gcyer) 

 and British America. Very variable in the size of the culm and character of the panicle, which 

 is usually slender and loosely flowered, sometimes reduced to a mere raceme of a few 1 -flowered 

 rays, and at the other extreme crowded and spike-like. The young states of this and S. Sibirica 

 very closely resemble one another, but that has longer rays naked below, the floret more copiously 

 silky and the anthers conspicuously bearded. The lower palet in S. viridula slightly projects 

 on each side of the insertion of the awn, and when that at length falls the soar is oblique. The 

 floret in both species becomes fuscous at maturity. 



26. ARISTIDA, Linn. TRIPLE-AWNED GRASS. 



Panicle racemose or spike-like, rarely spreading. Spikelets 1 -flowered. Glumes 

 unequal, the lower shorter, membranaceous, sometimes with a bristle-like point. 

 Floret oval or cylindrical, with an obconic mostly hairy callus and readily falling at 

 maturity. Lower palet chartaceous or coriaceous, longer than and inclosing the 

 upper, entire at apex where it bears a three-parted awn, with or without a joint at its 

 base. Scales 2. Stamens 3 ; anthers beardless. Ovary stipitate : styles distinct. 

 Grain cylindrical, inclosed in the lower palet, but free from it. 



Over 150 species are enumerated, of which the larger share belong to warm countries. The 

 culms, from an annual or perennial root, are often much branched ; the leaves narrow and mostly 



