MANUAL OF THE GRASSES OF THE UNITED STATES 



499 



1. Tripogon spicatus (Nees) Ek- 



man. (Fig. 733.) Culms 10 to 20 cm. 

 tall ; spike from one-fourth to half the 

 entire height of the plant; spikelets 

 5 to 8 mm. long. % — Rocky hills, 

 central Texas, Mexico; Cuba; South 

 America. 



100. ELEUSINE Gaertn. 



Spikelets few to several-flowered, 

 compressed, sessile and closely imbri- 

 cate, in 2 rows along one side of a 

 rather broad rachis, not prolonged 

 beyond the spikelets; rachilla disar- 

 ticulating above the glumes and be- 

 tween the florets; glumes unequal, 

 rather broad, acute, 1-nerved, shorter 

 than the first lemma; lemmas acute, 

 with 3 strong green nerves close to- 



Figuee 733. — Tripogon spicatus. Plant, X H; spikelet and floret, X 5. (Nealley 78, Tex.) 



side of a slender rachis, the rachilla 

 disarticulating above the glumes and 

 between the florets ; glumes somewhat 

 unequal, acute or acuminate, narrow, 

 1-nerved; lemmas narrow, 3-nerved, 

 bearing at base a tuft of long hairs, 

 the apex bifid, the midnerve extend- 

 ing as a short awn. Our species a low, 

 tufted perennial, with capillary blades 

 and slender solitary spikes, the spike- 

 lets somewhat distant. Type species, 

 Tripogon bromoides Roth. Name from 

 Greek treis, three, and pogon, beard, 

 alluding to the hairs at the base of the 

 three nerves of the lemma. 



gether, forming a keel, the uppermost 

 somewhat reduced; seed dark brown, 

 roughened by fine ridges, loosely en- 

 closed in the thin pericarp. Annuals, 

 with 2 to several rather stout spikes, 

 digitate at the summit of the culms, 

 sometimes with 1 or 2 a short dis- 

 tance below, or rarely with a single 

 spike. Type species, Eleusine cora- 

 cana. Name from Eleusis, the town 

 where Demeter was worshipped. 



1. Eleusine indica (L.) Gaertn. 

 Goosegrass. (Fig. 734.) Branching 

 at base, ascending to prostrate, very 

 smooth; culms compressed, usually 



