SYNOPSIS OF THE FLOEA OF COLORADO. 147 



awned above the middle, the outer side 2-nerved, the inner margin 

 much narrower and infolded, the upper glume emarjrinate or erose, cus- 

 pidate with a strong mid-nerve, the broader outer side also 2-3-uerved ; 

 pa-lets emarglnate or irregularly toothed at the apex, the lower 3-nerved, 

 the upper 2 nerved. Greene. 



BOUTELOUA OLiGrOSTACHYA, Torr. Hall & Harbour, 636. Near Den- 

 ver, Dr. Smith. B. H. Smith. Colorado Springs, Porter. Canon City, 

 Brandegee. Common on the plains. 



BOUTELOUA HIRSUTA, Lag. South Park, Canby. 



BOUTELOUA CURTIPEXDULA, Gray. Hall & Harbour. Colorado 

 Springs, Porter. 



BrcHLOE 1 DACTYLOIDES, Engelm. Trans. Saint Louis. Acacl., vol. 

 1, p. 432, pi. 12and 14. Densely tufted, spreading by stolons, forming- 

 broad mats; culms 3'-6' long; flowering stems of the male plant 4'-6' 

 long, glabrous or slightly hairy; leaves 2'-4' long, J"-!^' wide, nearly 

 smooth ; sheaths striate, glabrous, strongly bearded at the throat: spikes 

 3"-6" long; spikelets alternate in 2 rows, uppermost abortive, bristle- 

 form, 2 // -3 // long; lower glume ovate lanceolate, with a scarious margin ; 

 upper glume twice longer, ovate ; lower palet convex, 3-nerved, upper 

 one 2-nerved, two minute scales at the margin and inside of the lower 

 palet ; stamens 3. Stems of the female plant much shorter than the 

 leaves, lt^-2' high; heads 3"-3" long; glumes becoming ligneous; 

 spikes or heads usually 2; at maturity becoming thick, extremely hard, 

 including the loose grain. The celebrated "buffalo-grass," known to 

 hunters and trappers as one of the most nutritious grasses, on which for 

 a part of the year subsist and fatten the immense herds of buffalo and 

 the cattle of the hunter and emigrant. It extends on the elevated plains 

 from the British Possessions southward and westward into Mexico and 

 Xew Mexico. ETuttall, who had only the male plant, referred it to the 

 genus Scsleria, and described it as 8. dactyloides (Gen. 1, p. 64.) Steudel 

 founded another genus on the female plant, Antephora axilliflora, (Glum. 

 1, p. 111.) The true relationship between them was first detected by Dr. 

 Engelmann, and clearly set forth by him in his masterly article iii the 

 Trans. Saint Louis Acacl. Plains around Denver, Dr. Smith. Hall & 

 Harbour, 637. 



SQUARROSA, Torr. Bot. Whippl, Pacif. E. E. Eep. 4, p. 158. 



1 BUCHLOE, Eugelui. Flowers dioecious, heteromorphous. Male plant. Spikes 1-sided 

 2-ranked ; spikelets 2-3-floweivd. Glumes 2, 1 -nerved, lower much smaller. Palets 2, of 

 equal length, longer than the glumes; lower one 3-nerved, mucronate; upper one 

 2-nerved. Squamuhein pairs, truncate, emarginate. Stamens 3; anthers linear. Rudi- 

 ment of an ovary none. Female plant. Spikes 1-3, short, capitate, oblique in the in- 

 volucrate sheaths of the upper leaves ; spikelets 1-flowered, crowded, upper floret abor- 

 tive, withering. Glumes 2 ; lower glume of the lowest spikelets 1-3 nerved, lanceolate - 

 subulate, with an herbaceous tip, or 2-3-cleft, lower side athinte to the back of the 

 upper glume : lower glumes of the other spikelets (internal as to the head) free, much 

 smaller, membranaceous, ovate-lanceolate, acute, 1-nerved; upper glumes (external) 

 connate at the base with the thickened rachis, at length like a hard, woody involucre, 

 ovate, nerveless,, pale, trifid at the herbaceous, nerved tip. Lower palet (internal as to 

 the head) shorter. 3-nerved, herbaceous, tricuspidate; upper palet shorter, 2-nerved. 

 Squamuhe as in the male flowers. Rudiments of the stamens 3, minute. Ovary lenti- 

 cular, glabrous, very short-stipitate ; stigmas much longer than the 2 erect terminal 

 styles, plumose with simple hairs, exsert from the apex of the flower. Caryopsis free, 

 included in a horny, at length deciduous head, sublenticular, flat on the outside, 

 (toward the lower palet.) convex on the inner side. 



-MrxnoA, Torr. Spike capitate, leafy; spikelets 3, 2-6-fl owered ; flowers sessile: 

 2-ranked : Terminal one abortive. Glumes 2, subopposite, much shorter than the flow- 

 ers, mucronate. Palea 2, herbaceous, rigid, in the lowest spikelet naked, mucronate or 

 short-awned, not keeled, equilateral, in the uppermost spikelet bearded toward the 

 base ; caryopsis very smooth, covered by the upper palea. 



