PAPERS ON BOTANY 151 
nald.) This species in the dwarf form was rather frequent 
in the stretch of shore under consideration, the whole plants 
being little over one centimeter high and consisting only of a 
short culm, a few blades, and the head of a single spikelet or 
two. 
2. Panicum sp? 
Not common; a remarkably small form, the parts being so 
niinute and material so scarce that identification was not satis- 
factory. One plant was only 17 mm. from root to tip of nead. 
3. Eragrostis hypnoides (Lam.) B. S. P., Creeping Era- 
grostis, . 
A rather common plant in the region in moist places, and, 
when conditions are favorable, especially abundant on mud 
flats between high and low water-marks, where it spreads ex- 
tensively, forming large round mats. During the summer of 
1910, low water prevailed without marked fluctuations of 
level, and shortly after the river had fallen the black, barren 
mud flats were quickly covered, as if by magic, by the minute 
seedlings of this grass which spread extensively over the flats, 
rooting at every point, the circular mats often being 18 inches 
or more in diameter. “Culms 1’-18’ long,” (Britton & Brown) 
“2-5 dm. long,” (Robinson & Fernald). Common along shore, 
the plants frequently being hardly more than 1 cm. long and 
bearing but 3 or 4 blades and a small spike. 
4. Cyperus diandrus Torr. Low Cyperus. 
A common plant of river and lake shores, thriving especially 
in moist sand. “Culms 27-15’ tall.” (Britton & Brown.) 
“Culms 0.5-4 dm. high” (Robinson & Fernald). Some very 
small plants hardly more than 1 cm. tall noted. 
5. Cyperus inflexus Muhl. Awned Cyperus. 
Fairly common in wet places, and generally reaching a nor- 
mal size. “1’-6’ tall,” (Britton & Brown). “2-20 cm. high,” 
(Robinson & Fernald.) Dwarf plants very common along 
the stretch of shore, the entire plants exceedingly minute, 
hardly so conspicuous as a plant of the greater duckweed, even 
if that evident. 
