116 BOTANICAL GAZETTE [ FEBRUARY 
beach, tearing up here and depositing there, excludes almost 
entirely the possibility of survival through that period. In 
other words, biennials and perennials are practically excluded 
from maturing flowers and fruits, although their vegetative struc: 
tures may flourish for a single season. In the summer the 
xerophilous conditions are extreme. Nowhere in the dune 
region are the winds more severe than here; the middle beach 
is close enough to the lake to feel all the force of its winds and 
yet far enough away for the wind to pick up sand from the 
lower beach and bring to bear upon the flora the intense severity 
of the sand-blast. No flora is more exposed to the extreme 
desiccating influences of the summer sun than that which grows 
upon the bare and open beach. Even though the roots caf 
as succulent plants inhabit deserts where no other high grace 
plants can grow, so, too, they are able to withstand the severe 
conditions of the beach. . : 
Along the entire eastern shore of the lake, the dominatt 
plant of the middle beach is Cakile Americanz. At many points 
this succulent crucifer is almost the only plant species found i . 
this zone, and it is always the chief character species. bas 
other fleshy annuals are very common tenants of the middle 
beach: Corispermum hyssopifolium and one of the spurges, Euphor : 
bia polygonifolia. It is a matter of interest to observe that 
of these three character plants of the middle beach, Cakile a® 
Euphorbia, are also characteristic inhabitants of the beach iss 
the Atlantic coast. The significance of the presence of thes 
be discussed in another place. The above plants are fat 7 
tributed uniformly over the middle beach. The favorite plact ] 
for growth is along the lines of débris previously referee | 
along these lines a greater number of seeds find lodgment oe | 
elsewhere, because the waves wash them up from lowef ©" 
and the protection of the driftwood prevents the winds 
