156 



GRAMINEAE. 



Sporobolus serotinus (Torr.) A. Gray. 



(Fig- 355-) 



Late-flowering Dropseed 



Agrostis serotina Torr. Fl. U. S. i: 88. 1824. 

 Sporobolus serotinus A. Gray, Man. 577. 1848. 



Glabrous and smooth or very nearly so. culms 

 6 / -i8 / tall, from an annual root, erect, slender, 

 simple. Sheaths short, confined to the lower part 

 of the culm; ligule less than y 2 " in length, irre- 

 gularly truncate; leaves y 2 " wide or less, slightly 

 scabrous above, flat, the basal one-third to half the 

 length of the culm, those of the culm 2 / -4 / long; 

 panicle 3 r -9' in length, the branches capillary, 

 erect or ascending, the lower i'-2%' long; spike- 

 lets about ft" long, the outer scales subequal, ob- 

 tuse, smooth or sometimes sparingly scabrous; 

 third scale twice the length of the outer ones, 

 acuminate. 



In wet sandy soil, Maine to Michigan, south to New 

 Jersey. Sept.^Oct. 



16. Sporobolus compressus (Torr.) Kunth. 



(Fig. 356.) 



Agrostis compressa Torr. Cat. PI. N. Y. 91. 1819. 

 Sporobolus compressus Knnth, Enum. i: 217. 1833. 



Culms i-2 tall, from a horizontal rootstock, stout, 

 simple, much compressed, smooth and glabrous. 

 Sheaths compressed, overlapping, sometimes scabrous 

 at the summit; ligule very short; leaves s'-io 7 long, 

 i" wide or less, folded, slightly rough; panicle 4 / -io / 

 in length, the branches erect or ascending, the lower 

 2'-3' long; spikelets about y%" long; outer scales sub- 

 equal, obtuse or somewhat acute, smooth and gla- 

 brous; third scale obtuse and apiculate, strongly scab- 

 rous, slightly exceeding the outer ones. 



In bogs, Ixmg Island and in the pine barrens of New 

 Jersey. Sept. -Oct. 



17. Sporobolus asperifolius (Nees & Meyen) Thurber. 



Dropseed. (Fig. 357.) 



Flat-stemmed Dropseed. 



Rough-leaved 



Vilfa asperifolia Nees & Meyen; Trin. Mem. Acad. St. 



Petersb. (VI.) 6:95. 1840. 

 Sporobolus asperifolius Thurber; S. Wats. Bot. Cal. 2: 



269. 1880. 



Culms 6 / -i8 / tall, erect from a decumbent and 

 branched base, smooth and glabrous. Sheaths short, 

 crowded and overlapping, the upper usually enclosing 

 the base of the panicle ; ligule ]* l n g erose-trun- 

 cate; leaves numerous, I'-^y-t' long, i"-i}4 f/ wide at 

 the base, acuminate, strict, often erect, flat, glabrous, 

 smooth beneath, very rough above ; panicle 3 / -8 / in 

 length, included at the base, rarely entirely exserted, 

 the capillary branches spreading or ascending, the 

 lower 2 / ~4 / long; spikelets occasionally 2-3-flowered, 

 %" long; outer scales subequal, acute, glabrous, spar- 

 ingly scabrous; third scale obtuse or acute, glabrous, 

 somewhat exceeding the second. 



Dry soil, Assiniboia to British Columbia, south to Mis- 

 souri, Nebraska, California and Mexico. Aug. -Sept. 



