BULLETIN 
TORREY BOTANICAL CLUB. 
Vol. 23. Lancaster, Pa., July 20, 1896. No. 7. 
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Notes on Potentilla.—ll. 
By P. A. RypDBERG. 
Another very natural group is that which clusters around P. 
rivalis. ‘Natson acknowledged only three species, viz.; P. supina, 
P. rwalis and P. Norvegica. Lehmann has ten species, of which 
six are American. To these six should be added P. Nicolletii (P. 
Supina Nicolletii Wats.), which is a fairly good species and also an- 
other, near P. millegrana, described in this paper. 
The characters of the group are: an annual or biennial root, a 
terminal style which is curved above and considerably thickened — 
near the base, small flowers, in which the petals seldom exceed 
the sepals, 5-20 stamens and small anthers whose two lobes are 
nearly spherical. 
POTENTILLA PARADOXA Nutt.; Torr. & Gray, Fl. N. Am. 1: 437. : 
1838. gee = 
FP. supina Michx. F\. Bor. Am. 1: 304. 1803. Not a 
It has been regarded as a form of the European P. supina, and - 
we still find it under that name in our manuals, notwithstanding — 
the fact that the principal distinction has been known since the — 
: time of Nuttall. It resembles 2 supina in the leaves, which are — 
Pinnate with several pairs of leaflets, but differs from it not only — 
by the swollen corky attachment of the achene, but also in the — 
Stouter and more upright habit, the larger and coarser leaflets and 
a truly cymose inflorescence. It ranges from eat York to Mon- 
tana and New Mexico. 
