494 
segments ovate, rather obtuse; rays yellow, elliptic-oblong, 10-14 
mm. long, undulately 3-toothed at the apex; achenes obovate, 
more or less constricted at both ends, about 6 mm. long, winged 
(Plate 315). 
In dry or rocky soil, Cullman, Alabama, October, 1885. 
A very distinct species of the confused genus Si/phium, related 
to what I take to be S. asperrimum Hook., hitherto usually called. 
S. scaberrimum., It is at once distinguished by the copious shaggy 
‘pubescence of its foliage as against the short retrorse pubescence 
of its relative. The peculiarly toothed leaves with their less 
rounded bases, and the smaller heads with their narrower bracts 
and shorter rays are additional distinguishing characters. 
The species is named in honor of the veteran botanist of Ala- 
bama, Dr. Charles Mohr, who for many years has furnished our 
collections with rare and unique plants from that interesting re- 
gion. 
IlI. THe True Position oF VIOLA TRIPARTITA ELL. 
The record of the occurrence of Viola hastata in Florida has al- 
ways been a puzzle to me, for that plant is as typical an Alle- 
ghenian species as our flora affords. 
During my field work in the Southern States I have had oppor- 
tunity to study the forms under consideration in their native habi- 
tats and have been led to the following conclusions, namely: 
That V. tripartita is specifically distinct from its relatives, and that 
it is closely related to V. pubescens and V. scadriuscula and not to 
V. hastata. It seems strange that Dr. Gray, and even the saga- 
cious Le Conte failed to observe the latter fact, for a casual glance 
at the foliage and flowers is sufficient to prove this position cor- 
rect, the sepals and petals of V. tipartita being much more 
similar to those of V. pubescens than to those of V. hastata. 
The question that naturally arises is: How was V. #ripartita 
ever confounded with V. fastata? As far as I can see this was 
brought about through observations on simple-leaved plants of 
V, tripartita; it is on simple-leaved specimens of this plant that 
V. hastata is admitted to the flora of Florida. The leaf form of 
the latter species is so distinct and unique that it need not be fur- 
ther considered in this connection. On the other hand the leaf 
form of V. éripartita in its simple state, which is quite frequent, 
