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; spikelets 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 littoralis Engelm. 
Monanthochloe Engelm., Trans. Acad. St. Louis 1: 1436. 1859. Only one 
species described. 
Monanthochloe littoralis (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 dicecious; 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 
