30 GRAMINEAE 



2. S. purpurea (Walt.) Kuntze. Sand-grass. A tufted anuual. 

 about 1° high : leaves short, sparingly oiliate : panicle J'-2' long. — In 

 sand in the Missouri Eiver bottom at Courtney. Common in one 

 locality. Also occurs at Quindaro, Kansas. July-September. 



38. DIPLACHNB Beauv. 

 Spikelets several-flowered, sessile on the rachis, forming slender 

 spikes. Two lower glumes empty, keeled, acute, unequal. Flowering 

 glumes longer, 1-3-nerved, 2-toothed and mucronate between the teeth. 



Spikelets i"-\" long. 1. D. fasdeularis. 



Spikelets 5"-6" long. 2. D. acuminata. 



1. D. fasoiculaiis (Lam.) Beauv. A decumbent or ascending annual, 

 l°-3° high : spikes panicled, partly enclosed in upper sheath : spikelets 

 3//_5// long, 5-11-flowered. — Often common on muddy shores in low 

 grounds. June-October. 



2. D. acuminata Nash. Resembles the last, bat spikelets longer, 

 the flowering scales acuminate, entire (obtuse and two-toothed in D. 

 fasdeularis). — Often common on mud-flats, especially at Courtney. 

 June-September. 



39. ERAGROSTIS Beauv. 



Spikelets paniculate, 2-many-flowered, flattened. Two lower glumes 

 empty, short and keeled, 1-nerved. Flowering glumes keeled, 3-nerved, 

 not pilose at base. Palet 2-nerved, persistent on the rachis after the rest 

 of the flower has fallen. 



Culms creeping and rooting. 1. liypnoides. 



Culms ascending or erect. 

 Spikelets large and flat, forming a narrow crowded 



panicle. 2. E. major. 



Panicle open, its branches capillary. 

 Culms 1J° high or less. 

 Spikelets 5-many-flowered. 3. E. Ptweliii. 



Spikelets 2-5-flowered. 



Culms much-branched. 4. E. Frankii. 



Culms sparingly branched. 5. E. capillaris. 



Culms 1J° or more high. 

 Spikelets yellowish, usually 3-5-flowered. 6. E. trichodes. 



Spikelets purplish, usually 6-10-flowered. 7. E. pectinacea. 



1. B. hypnoides (Lam.) B.S.P. Annual, forming large patches 

 leaves short, 6"-18" long : flowering branches 2'-5' high : spikelets 

 dioecious, 10-30-flowered, 2"-8" long, clustered.— Common along 

 streams, especially along the Missouri River. June-October. 



2. E. major Host. 6'-2J° high: leaves flat, sharp-pointed, 4'-6' 

 long : panicle 2'-6' long, 1J'-2J' wide : spikelets lance-oblong, 3"-6" 

 long, IJ" wide, usually 8-20-flowered. — Common in waste places. 

 July-October. 



3. E. Purshii Sohrad. Densely-tufted and much branching, 3'-18' 

 high : leaves about 2' long : panicle from I'-IO' long, its branches loose 



