158 



GBAMINEAE (GRASS FAMILY) 



72. SCOL6CHLOA Link. 



Spikelets 3-4-flowered ; callus hairy ; glumes acute ; lem- 

 mas firm, convex below, the nerves unequal, one or more 

 excurrent as slender teeth ; palea as long as its lemma or 

 longer, 2-toothed ; ovary hairy at the summit. Tall peren- 

 nials with flat leaves arid ample spreading panicles. (Name 

 probably from o-xwXos, a prickle, and x^a, grass.} 



1. S. festucacea (Willd.) Link. (SPRANGLE-TOP.) Culms 

 stout, erect, from thick soft rootstocks, 1-2 in. high ; leaves 

 2-3 dm. long ; panicles 1.5-3.5 dm. long, the fascicled 

 branches spreading ; spikelets 6-12 mm. long ; glumes nearly 

 as long as the florets, 3-5-nerved. Marshes and shallow 

 water, la., Minn., and northwestw. June, July. FIG. 168. 



73. GLYCERIA R. Br. MANNA GRASS 



Spikelets few-many-flowered, subterete or slightly compressed, in narrow 

 or spreading panicles ; glumes unequal, shorter than the florets ; lemmas convex, 

 firm, with a scarious margin or apex, and 5-9 strong parallel nerves; paleas 

 equaling or a little longer than their lemmas, the strong nerves nearly marginal. 

 Usually tall aquatic perennials, with simple culms, often partially closed sheaths, 

 flat leaves and terminal panicles. (Name from y\vi<ep6s, sweet, in allusion to 

 the taste of the grain.) PANICULARIA Fabricius. 



S. festucacea. 

 Panicle x Vio- 

 Spikelet and floret x 1. 



Spikelets 2-7 mm. long, ovate or oblong. 

 Panicle contracted, narrow. 



Panicle linear, 1.5-3 dm. long 



Panicle oblong, dense, 7-12 cm. long 



Panicle open, lax. 

 Spikelets 3-4 mm. wide ; lemmas obscurely nerved. 



Spikelets ovate, 5-10-flowered 



Spikelets oblong, 3-5-flowered 



Spikelets not over 2.5 mm. wide ; lemmas strongly nerved. 



Second glume 1 mm. long 



Second glume 2-2.5 mm. long. 

 Panicles ample, many-flowered, 2 dm. or more long 

 Panicles narrow, few-flowered, rarely 1.5 dm. long 

 Spikelets 1-4 cm. long, compressed-cylindric. 

 Lemma obtuse ; palea about the same length. 



Lemma 6 mm. long 



Lemma 84.5 mm. long. 



Spikelets 1.5-2 cm. long, subsessile or nearly so . . . . 

 Spikelets 1-1.5 cm. long, on slender pedicels one third to two thirds 



as long 



Lemma acute, much exceeded by the palea '. 



1. O. Torrei/dii. 



2. G. obtn*<t. 



3. G. canadensis. 



4. G. taxa. 



5. G. nervata. 



6. G. (/r<ritifs. 



7. G.palUda. 



8. G.Jlnit<t)<. 



!>. (,'. .v- j>t, >< frionti/ix. 



10. G. borealis. 



11. G. a 



1. G. Torreyana (Spreng.) Hitchc. Culms solitary or few, erect from a 

 running rootstock, 6-9 dm. high ; the smooth sheaths closed nearly to the sum- 

 mit; blades 3 dm. or more long, 3-6 mm. wide, scabrous; panicle linear, 1.5-3 

 dm. long, nodding at the summit; spikelets appressed, 3-4-flowered, about \ mm. 

 long. (G. elongata Trin.) Wet woods, Que. to Minn, and Pa., and in the 

 mts. to N. C. July, Aug. 



2. G. obtusa (Muhl.) Trin. Culms stout, erect, 3-12 dm. high ; shi-nths <-lnm-d 

 about half their length, the lower overlapping; blades 2-5 dm. long, 4-8 nun. 

 wide, smooth below, rough above ; panicle finally exserted, 



oblong, dense, 6-18 cm. long; spikelets 3-7-flowered, 5-6 mm. 

 long; the scarious apex of the lemma often revolute. Bogs 

 and swampy places, N. B. to Pa., and south w. near the coast. 

 July, An- ' 



'>. G. canad6nsis (Michx.) Trin. RATTLESNAKE GRASS. 

 ( 'ulins solitary or few, stout, erect, 6-10 dm. hi^h ; sheaths over- 

 lapping below, compn-ssnl ; bladrs 1..~i-:!.f, dm. long, 4-8 mm. 

 wide, scabrous; panirl,' !.."> :; dm. long, nearly as wide, very i !'.'. <;. 

 loose and open, the capillary remote branches drooping, naked Spikelet x 8. 



