62 American Midland Naturalist Monograph No. 2 



54. Anthoxanthum L. 



A. odoratum L. Sweet Vernal Grass. Meadows, roadsides, waste places; 

 nat. from Eurasia. May-July. 



55. Phalaris L. — Canary Grass 

 1. Panicle 8-15 cm. long; spikelets 5-6 mm. long, the glumes not winged; 



marshes and wet meadows. May-July. Reed Canary Grass 



- P. arnndinacea L. 



1. Panicle ovoid, 1-4 cm. long; spikelets 6-8 mm. long; the glum'es winged; 



roadsides and waste places; nat. from Eur. June-July. Canary Grass 



P. canariensis L. 



56. Leersia Sw. 



(^Homalocenchnis Mieg.) 

 1. Spikelets broadly oval, densely imbricate, 3-4 mm. wide; stem terete; moist 



ground. Aug.-Oct. Catchfly Grass L. lenticularis Michx. 



1. Spikelets elliptical, 1-2 mm. wide. 



2. Spikelets 3-3.5 mm. long; stamens 1 or 2; leaves nearly smooth; stem 



compressed; moist woods. July-Sept. White Grass. ...L. virginica Willd. 



2. Spikelets 4-4.5 mm. long; stamens 3; leaves very rough; stem terete; wet 



ground. Aug. -Sept. Cut Grass L. oryzoides (L.) Sw. 



57. ZiZANiA L.— Wild Rice 

 1. Blades 4-10 mm. wide; body of the pistillate lemma 10-17 mm. long; usually 



in shallow water, July-Sept. [Z.. palustris sensu auth., non L.] 



Z.- aquatica L. 



1. Blades 1-5 cm. wide; body of the pistillate lemma 2-3 cm. long; shallow 



water. July-Sept Z.- interior (Fassett) Rydb. 



58. DlGlTARiA Heist. 

 (Svnlherisma Walt.) 

 1. Rachis of the racemes wingless; spikelets 1.5-1.8 mm. long; lower sheaths 

 pilose, the upper ones glabrous; stems usually erect; sandy soil. Aug.-Sept. 



D. flijormii (L.) Koel. 



1. Rachis winged; stems spreading, often rooting at the lower nodes. 



2. Sheaths glabrous; pedicels terete or nearly so; spikelets 2 mm. long; fields, 

 meadows, waste ground, roadsides, common; nat. from Eurasia. 



Smooth Crab Grass \^Syntherisma linearis (Krock) Nash] 



D. ischaemum (Schreb.) Muhl. 



2. Sheaths pilose; pedicels 3-angled, scabrous; spikelets 3-3.5 mm. long; 

 a common weed in cult, ground and waste places; nat. from Eur. July- 

 Oct. Common Crab Grass D. sangiiinalis (L.) Scop. 



59. Leptoloma Chase 

 L. cognatum (Schult.) Chase. Sandy soil. July-Sept. 



60. Paspalum L. 



1. Rachis of the spikes dilated, thin, more than 2 mm. broad, with membran- 

 ous margins. 



