56 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 



to hold in place with its numerous creeping rhizomes. The species 

 is found from South Dakota to Kansas. It has little value for 

 forage but much value as a sand binder. 



16. MONANTHOCHLOE Engelm. 



Plants dioecious; spike-lets 3 to 5 flowered, the uppermost florets 

 rudimentary, the rachilla disarticulating tardily in pistillate spike- 

 lets; glumes wanting; lemmas rounded on the back, convolute, nar- 

 rowed above, several-nerved, those of the pistillate spikelets like 

 the blades in texture; palea narrow, 2-nerved, in the pistillate spike- 

 lets convolute around the pistil, the rudimentary uppermost floret 

 inclosed between the keels of the floret next below. 



A creeping wiry perennial, with clustered short subulate leaves, the 

 spikelets at the ends of the short branches only a little exceeding the 

 leaves. Species two, one on muddy shores of the ocean in tropical 

 America, one in Argentina. 



Type species: Monanthochloe Httoralis Engelm. 



Monanthochloe Engelm., Trans. Acad. St. Louis 1: 1436. 1859. Only one 

 species described. 



M onanthocJiloe Httoralis (fig. 23) is found within our limits only 

 in southern Florida, southern Texas, and southern California, on 

 tidal flats, sometimes covering extensive areas. Owing to the incon- 

 spicuousness of the spikelets, the flowering stage can be determined 

 only on close examination. The species has no economic importance 

 except as it tends to convert mud flats into permanent soil. 



The leaves next the spikelet are reduced, but always present a 

 short though well-marked blade or foliaceous tip with a distinct 

 ligule. The branches bearing the spikelets are short and clustered. 

 The uppermost leaf, the one nearest the spikelet, usually has no bud 

 or branch in its axil. The leaf next below bears a bud or short 

 branch and a well-developed prophyllum. The prophylla of 

 branches somewhat lower may be 'as large as the sheath of the leaf, 

 and the two nerves may extend into prominent foliaceous tips. As 

 the branch develops, the prophyllum usually splits down the middle 

 and the two halves stand one on each side. The uppermost leaf 

 sometimes has in its axil a thin membranaceous nerveless obtuse 

 bract which clasps the spikelets like a second (upper) glume, but 

 probably this is to be interpreted as a prophyllum, subtending a 

 branch which failed to develop. 



17. DISTICHLIS Raf. 



Plants dioecious; spikelets several to many flowered, the rachilla 

 of the pistillate spikelets disarticulating above the glumes and 

 between the florets; glumes unequal, broad, acute, keeled, mostly 



