146. Gramineae 345 



Tribe 8. Oryzeae. — Rice Tribe 

 63. Leersia Sw. 



l.Spikelets broadly oval, densely imbricate, 3-4 mm wide; stem 

 terete; moist ground, locally throughout 111. except the n. coun- 

 ties. Aug.-Oct. Catchfly Grass L. Icnticularis 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. 



64. Zizania L. — Wild Rice 



Z. aquatic a L. Borders of streams, ponds, and lakes, usually in 

 shallow water, chiefly in n.e. 111., and in the valley of the Illinois and 

 Mississippi rivers; lormerly more common. July-Sept. [Z. interior 

 (Fassett) Rydb.]. 



Subfamily II. Panicoideae 



Tribe 9. Paniceae. — Millet Tribe 



65. Digitaria Heist. 



1. Rachis winged, 0.7-1 mm wide; stems .spreading, often rooting at 

 the lower nodes. 

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

 long; a common weed in cultivated ground, lawns, and waste 



places; nat. from Eur. July-Oct. Common Crab Grass 



...D. sanguinalis (L.) Scop. 



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

 long; fields, meadows, waste ground, roadsides, common; nat. 



from Eurasia. July-Oct. Smooth Crab Grass 



- D. ischacryium (Schreb.l Muhl. 



1. Rachis of the racemes wingless, about 0.3 mm wide; spikelets 1.6- 

 2 mm long; lower sheaths pilose, the upper ones glabrous; stems 

 usually erect; sandy soil, infrequent, chiefly in the w. central 

 counties. Sept. -Oct. Finger Grass. [D. villosa (Walt.) Pers.] 

 - D. filiformis (L.) Koel. 



66. Trichachne Nees 



T. insularis (L.) Nees. Sour Grass. Roadsides. Williamson Co., 

 J. W. Voigt in 1954; adv. from s.e. U.S. 



67. Leptoloma Chase 



L. cognatum (Schultes) Chase. Fall Witch Grass. Sandy soil, 

 locally throughout 111. July-Sept. 



