GENERA OF GRASSES OF THE UNITED STATES. 175 



tance below, or rarely with a single terminal spike. Species about 

 six, in the warm regions of the Eastern Hemisphere, one a common 

 introduced weed in America. 



Type species: EJeusine coracana Gnertn. 



Eieusine Gaertn., Fruct. and Sem. 1 : 7, pi. 1, f. 11. 1788. Two species are 

 described, E. coracana and E. indica. The first, being figured, is selected as the 

 type. 



Eleusine indica (L.) Gaertn. (fig. 103) is a common garden and 

 roadside weed throughout the warmer parts of America, extending 

 northward to Illinois and Massachusetts. It is usually spreading or 

 prostrate, with two to several spikes, or rarely one. This species is 

 sometimes called goose-grass and yard-grass. 



The type species of the genus, Eieusine coracana Gaertn., is culti- 

 vated in the Tropics of the Old World for the seed, which is used for 

 human food by the poor or primitive people. It differs from 

 E. indica in its larger size, stouter, often incurved spikes, and globose 

 seed. 



85. DACTYLOCTENITJM Willcl. 



Spikelets 3 to 5 flowered, compressed, sessile and closely imbricate, 

 in two rows along one side of the rather narrow flat rachis, the end 

 projecting in a point beyond the spikelets; rachilla disarticulating 

 above the first glume and between the florets; glumes somewhat un- 

 equal, broad, 1-nerved, the first persistent upon the rachis, the second 

 mucronate or short-awned below the tip, deciduous; lemmas firm, 

 broad, keeled, acuminate or short-awned, 3-nerved, the lateral nerves 

 indistinct, the upper floret reduced; the palea about as long as the 

 lemma ; seed subglobose, ridged or wrinkled, inclosed in a thin, early- 

 disappearing pericarp. 



Annual or perennial grasses, with flat blades and two to several 

 short thick spikes, digitate and widely spreading at the summit of 

 the culms. Species three, in the warmer parts of the Eastern Hemi- 

 sphere, one a common weed in tropical America. 



Type species: Cynosurus aegyptius L. 



Dactyloctenium Willd., Enum. PI. 1029. 1809. Willdenow describes but one 

 species, D. aegyptiacum, based on Cynosurm aegyptius L. 



Our only species is Dactyloctenium aegyptium (L.) Richt. 

 (D. aegyptiacum Willd.) (fig. 104), a tropical weed which extends 

 northward to New York and Illinois. It is a prostrate annual with 

 2 to 5 spikes, often forming mats rooting at the nodes. Sometimes 

 called crowfoot grass. 



86. CAPRIOLA Adans. 

 (Cynodon Rich.) 



Spikelets 1 -flowered, awnless, sessile in two rows along one side of 

 a slender continuous rachis, the rachilla disarticulating above the 

 glumes and prolonged behind the palea as a slender naked bristle, 



