180 



GRAMINEAB (GRASS FAMILY^) 



Ptinicles contracted. 

 Rootstocks short or slender or none ; culms tufted or solitary. 

 Panicle not more than one-third the entire height of the plant. 

 Perennials. 

 Spikelets 5 mm. long or more ; panicle dense. 

 Floret appressed-pubescent below. 

 Lemma two-thirds as long as palea . 



Lemma and palea subequal 



Floret glabrous 



Spikelets not over 4 mm. long; panicle interrupted. 

 Culms smooth; ligule 0.5 mm. long .... 

 Culms minutely roughened by septae ; ligule 2 mm. long 

 Annuals. 

 Spikelets 4 mm. long ; lemma pubescent , 

 Spikelets 2.5-3 mm. long; lemma glabrous 

 Panicle one-third to one-half the entire height of the plant . 



Kootstocks stout, extensively creeping 



Panicles open (often contracted la no. 10). 

 Glumes very unequal. 

 Spikelets 2.5-3 mm. long ; glumes ovate or lanceolate. 

 Sheaths bearded at the throat ; blades flat .... 

 Sheaths not bearded ; blades involute .... 

 Spikelets 4-6 mm. long; first glume awl-shaped . 

 Glumes subequal. 

 Plants compressed at base ; leaves conduplicate . . 

 Plants not compressed; leaves flat 



1. 8, otande/tUnufi. 



2, S< ca/novirena. 

 8. S. aaper. 



4. 8. brevi/olius. 



5. S. Riehardsonis. 



6. S. vaginiJiorU8t 



7. S. neglectu*;. 



8. S, indicus. 



9. -S'. mrginicua. 



10. 8. cryptandrua. 



11. S.junceua, 



12. 8.'heterolepia, 



18. 8. compreaaua. 



14. 8* unijiorua. 



1. S. clandestinus (Spreng.) Hitchc. Tufted culms 4-12 dm. high ; lowei 

 leaves long, subrigid, the margins and involute-filiform tips scabrous; panicle 

 5-16 cm. long, often partially inclosed in the upper sheath ; spikelets 

 6-8 mm. long ; glumes unequal, acute, the first J the length of the 

 acute lemma, the second J that of the long-aeuminate pointed palea ; 

 lemma and palea appressed-pubescent toward the base, the lemma | 

 the length of the palea. (S. asper Man. ed. 6.) — Sandy fields and 

 dry hills, Ct. to 111. , Mo. , and southw. Sept. Fig. 96. 



2. S. can(5virens Nash. Similar to the preceding but smaller ; 

 the shorter leaves hirsute near the base ; panicle smaller ; spikelets 

 about 6 mm. long ; lemma and palea acute, subequal. — Sandy soil, 

 Tenn., Mo., and southw. 



3. S. ilsper (Michx.) Kunth. Culms stout, 3.6-10 dm. high ; 

 96. S. eland, sheaths overlapping ; blades nearly as long as the culm, the upper 

 Spikeletx3. exceeding the panicle, pilose above at the flat base, the long involnte- 



flliform tip scabrous; terminal panicle 8-25 cm. long, partly in- 

 cluded in the inflated upper sheaths, lateral panicles small, usually hidden in 

 the sheaths, or none; spilselets 5-6 mm. long; glumes unequal, obtuse or sub- 

 acute, the first about ^ as long as the floret ; lemma and palea glabrous, the 

 lemma slightly the longer. (S. longifolius Wood.) — Dry 

 sandy soil. Me. to S. Oak., and southvf. Fig. 97. 



4. S. brevifbllus (Nutt.) Scribn. Tufted culms 3-6 dm. 

 high, very slender ; leaves involute-filiform ; ligule 0.5 mm. long, 

 erose-truncate ; panicle very slender, loosely flowered, 6-10 cm. 

 long ; spikelets about i mm. long ; glumes acuminate, subequal, 

 I as long as the short-cuspidate lemma, which slightly exceeds 

 the palea. (6^. cuspidatus Wood.) — i)ry open ground. Wis. 

 to Mo., and westw. 



5. S. Hichardsbnis (Trin.) Merr. Similar to the preceding, 

 2-5 dm. high ; culms erect or ascending from a slender horizontal rootstock, 

 minutely roughened by septae ; ligule 2 mm. long, acute ; panicle 1-6 (rarely 10) 

 cm. long; spikelets somewhat crowded, 3 mm. long; glumes acute, less than 

 J as long as the cuspidate lemma {the cusp about 1 mm. long) which exceeds 

 the palea. (S. cuspidatus, in part, and S. depauperatus Man. ed. 6; S. brevi- 

 folius Nash, as to description, not Scribn.) — Meadows and along rivers, N. B. 

 and Me. ; Neb., and in the far West. Aug. 



6. S. vaginiflbrus (Torr.) Wood. Tufted culms 2-6 dm. high, slender, 

 erect to widely spreading ; leaves about 2 mm. wide, involute toward the end; 

 jinnicles numerous, partially included in the inflated sheaths, or the terminW 



97. S. asper. 

 Spikelet X 8. 



