ee ee ee ee ee ee Se ee a a 
eee et ee ae sh ee i A a le a 
1894. ] Botanical Notes from Bainbridge. 35 
degrees from the perpendicular towards the north, Since 
then (in three years) the upper twenty-five feet of the tree 
had distinctly curved back towards a perpendicular, being in- 
clined only about seven degrees. That it should have done 
so considering the thickness of the trunk even at this distance 
(thirty feet) from the ground seems strange. 
A new compass-plant. 
A walk through any bit of open woodland in July is certain 
to reveal the presence of quite a number of plants whose 
leaves have assumed a more or less vertical, instead of hori- 
zontal position, owing to a twist in the petiole, or, if the leaf 
be sessile, in the lower part of its blade, near the base. This 
is especially common among the Composite, where such 
names as Seriocarpus tortifolius Nees, and, possibly, So/- 
dago tortifolia Ell. record the fact. A species of Aster, with 
ovate-oblong leaves, having a sessile, cordate base, shows a 
strong twist of the entire leaf towards the right or towards 
the left, but often in the samedirection over the major portion 
of the same plant. 
In Sericocarpus tortifolius the twist is confined to the nar- 
rowed base of the leaf; in some plants the twist is such that 
most of the lower leaves turn their upper surfaces towards the 
south, while the upper younger leaves do not show this ten- 
dency; in other plants even the lower leaves show no regular- 
ity as to which side is presented to the sun. 
In various species of Liatris the twist is confined more 
or less to the lower half or third of the leaf and the twist is 
quite regularly in the same direction, so that looking at the 
plant from above the twist of the leaf blades gives it an effect 
a little like that of ascrew. In general the twist is such that, 
holding the stem so as to place the leaf to be examined to- 
ward the right hand of the spectator, the upper surface of the 
leaf is directed towards him. Liatris scariosa Willd. shows 
this arrangement and Liatris graminifolius Willd. gives the 
screw-like effect very strongly. Other species of the genus 
show it. In a less distinct manner Hypericum angulosum 
Michx. shows the twisting of the leaf blades. 
hat is the meaning of this twisting of the leaf blade? 
Where the leaf blade is twisted throughout its entire. ex- 
tent the Cause may be a little dubious, but where the twist- 
ing is confined to the basal portion of the leaf it seems quite 
evident that the resulting vertical portion of the leaf blade is 
