^30 GRAMINEAE QGRASS FAMILY) 



Panicles 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 . . . . . 1. o. clandentin/us. 



Lemma and palea subequal . 2. <S. canovirenB. 



Floret glabrous ..... .... 3. ^. asper. 



Spikelets not over 4 mm. long; panicle interrupted. 



Culms smooth ; ligule 0.5 mm. long . . . . , A. S. brem/oliu8. ^ 



Culms minutely roughened by septae ; ligule 2 mm. long , 5. /S. Richard sonis. 



Annuals. 

 Spikelets 4 mm. long ; lemma pubescent . . Q. S. vaginijlorua, 



Spikelets 2.5-3 mm. long; lemma glabrous 7. S. neglectus. 



Panicle one-third to one-half the entire height of the plant , . - 8. S.indicus. 

 Root.stocks stout, extensively creeping .... 9. <S'. virginicus. 



Panicles open (often contracted in no. 10). 

 Glumes very unequal. 

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



Sheaths bearded at the throat ; blades flat .10. S. cryptandrua. 



Sheaths not bearded ; blades involute 11. S.junceus. 



Spikelets 4-6 mm. long ; first glume awl-shaped 12. /S. heterolepU. 



Glumes subequal. 

 Plants compressed at base; leaves conduplicate . ...» 13. S. compressus. 

 Plants not compressed ; leaves flat 14. xS'. vm.iJtorus. 



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

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

 6-15 cm. long, often partially inclosed in the upper sheath ; spikelets 

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

 acute lemma., the second \ that of the long-acuminate pointed palea ; 

 lemma and palea appressed-puhescent 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 south w. Sept. Fig. 96. 



2. S. can6virens Nash. Similar to the preceding hut 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 south w. 



3. S. asper (Michx.) Kunth. Culms stout, 3.5-10 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 involute- 

 filiform 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; spikelets 5-6 mm long; glumes unequal, obtuse or sub- 

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

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

 sandy soil. Me. to S. Dak., and south w. Fio. 97. 



4. S. brevifblius ('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, 5-10 cm. 

 long ; spikelets about 4 mm. long ; glumes acuminate, subequal, 

 f as long as the short-cuspidate lemma, w^hich slightly exceeds 

 the palea. {S cuspidatus Wood.) — Dry open ground, Wis. ^^ s asper 

 to Mo. , and westw. Spikeiet x 3* 



5. S. Richards5nis (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 

 ^ as long as the cuspidate lemma {the cusp about \ 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. 



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

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

 panicles numerous, partially included in the inflated sheaths, or the terminal 



