158 



GRAMINEAE (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 and ample spreading panicles. (Name 

 probably from <r/c<2Xo?, a prickle, and %X6a, grass.") 



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

 stout, erect, from thick soft rootstocks, 1-2 m. 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. 



168. S. festucacea. 

 Panicle x y^. 

 Spikelet and floret x 1. 



1. G. Torreyana. 



2. G. obtusa. 



3. G. canadensis. 



4. G. laxa. 



5. G. nervata. 



6. G. grandis. 

 1. G.pallida. 



8. G.fluitans. 



9. G. septentrionalis. 



10. G. borealis. 



11. G. ac 



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

 Panicle contracted, narrow. 



Panicle linear, 1.5-8 dm. long 



Panicle oblong, dense, 712 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 3-4.5 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. 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 4 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 ; sheaths closed 

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

 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 southw. near the coast. 

 July, Aug. 



3. G. canadensis (Michx.) Trin. RATTLESNAKE GRASS. 

 Culms solitary or few, stout, erect, 6-10 dm. high ; sheaths over- 

 lapping below, compressed; blades 1.5-3.5 dm. long, 4-8 mm. 



wide, scabrous ; panicle 1.5-3 dm. long, nearly as wide, very 169. G. canadensis, 

 loose and open, the capillary remote branches drooping, naked Spikelet x 3. 



