ACJROSTIDK.E. 219 



Pennsylvania, Scribner 266; Delaware, Canhy; also Lake Co., 

 Micliigan. 



^'ew England, Michigan, Wisconsin, and southward. 



11. S. flexuosa Yasey, Bull. Torr. Club, 15:49 (1888). 

 Culms erect, scabrid, 70-00 cm. high. Sheaths longer than the 



internodes; lower ligule 1 mm. long, the upper 5 mm. long; blades 

 of sterile shoots about half as long as the culm, those on the culm 

 3 in number, the upper 10-18 cm. long. Panicle exserted when 

 mature, thin, 12-25 cm. long; rays in threes, fours, or fives, 

 spreading, the lower clusters 7-9 cm. distant from the next above, 

 longest rays 10 cm. long, l^earing a few spikelets near the apex. 

 Empty glumes purplish, linear-lanceolate, 3-nerved at the base, 

 first 11-13 mm. long with a very slender apex, second 7-10 mm. 

 long; floret pubescent, 6-7 mm. long, including the curved acute 

 callus below, and a short crown of hairs at the apex; awn once 

 bent, about 6 cm. long; palea 2 mm. long. 

 Mexico, Pringle 384. 



12. S. coronata Thurb. S. Wats. Bot. Calif. 2:287 (1880). 8. 

 Stillmannii Boland. Proc. Calif. Acad. 4: 169 (1870). 



An erect grass, 120-180 cm. high, the culm often 6-8 cm. 

 diam. Sheaths very loose; ligule very short and a ciliate fringe; 

 Hades about 4 in number, scabrid above and sometimes below, the 

 lower often 90 cm. long, 8-12 mm. wide, from the base gradually 

 tapering into a very slender involute point, the upper one filiform, 

 15 cm. long. Panicle often partially included by the inflated 

 upper sheath, narrow, many-flowered, 30-40 cm. long, lower 

 branches in twos or threes, some of them often 15 cm. long. 

 Empty glumes pale green, tinged with purple, acuminate and 

 bristle-pointed, first 3-5-nerved, 16-22 mm. long, second 5-nerved 

 and 12-20 mm. long; floret to the joint, including the short sharp 

 curved callus, 9-10 mm. long, clothed with silky hairs, the upper 

 of which are 4 mm. long; apex bifid, hairy, awn slender, twice 

 bent near the middle, about 2.5 cm. long; palea 4-5 mm. long. 

 Stamens 3; anthers naked. 



S. Stillmannii Bolander is a small form of this species. 



