270 SEMI-CENTENNIAL OF ToRREY BOTANICAL CLUB 
Fire. Fire seems to be a normal environmental factor in this 
prairie, as in all others more than a few acres in extent,* but just 
what its normal frequency may have been in prehistoric times 
it is impossible now to determine. Nearly all the herbs and shrubs 
have thick or matted subterranean rootstocks, so that they sprout 
up again readily after a fire. Plants with barbed fruits (which 
are most effective in dissemination if they remain on the plant 
for several months) seem to be entirely absent, and shrubs with 
nuts or berries generally grow in clumps, whose centers are thus 
.2. Edge of oak grove near the railroad, about two miles north of Hicksville, 
A pin S.S.E., showing Quercus Marylandica, О. stellata, and the herbaceous vegeta- 
tion characteristic of dry prairies. 12:20 p.m., Oct. 20, I907. The trees evidently 
have, and need, little or no protection from fire running through the grass. (The 
view in Torreya 12: 282 was taken from the same point.) 
protected from fires of moderate intensity. "Woody vines (all 
of which seem to be sensitive to fire) are scarce, and chiefly 
confined to the clumps of bushes in the eastern part and to the 
valleys. The commonest tree on the Plains, the gray birch, is 
often partly protected by a cluster of shoots around its base, and 
it is rather short-lived anyway, so that young trees spring up as 
ж See Plant World 20: бо. “Feb.” 1017. 
