394 
paticae. Our knowledge of the distribution of species is very much 
limited. We know next to nothing of the Hepaticae of the en- 
tire range of the Rocky Mountains south of northern Idaho, and 
Mr. Leiberg and others who have sent in considerable quantities of 
interesting plants from farther north have only shown us the stores 
of information awaiting the collector in that region. Colorado, 
Utah, the Sierras from Oregon southward, and all the Southwest 
from Missouri to Texas, New Mexico and Arizona are a great 
unknown, no less among all of the lower cryptogams than in the 
Hepaticae. Much more needs to be done throughout all the 
States of the Mississippi valley, and especially the southern 
extension of the Appalachian area, which needs the careful atten- 
tion of the resident observer, rather than the hasty notes of the 
transient collector. It is hoped that the above synopsis and de- 
scriptions will be sufficient to provide for any student of the group 
the ready means of identifying his material; we shall be pleased 
to receive doubtful material, or that illustrating additional facts of 
distribution. 
New York, 24 September, 1896. 
Notes on Potentilla.—-lV. 
By P. A. RyDBERG. 
( Plates 274 and 275.) 
The Aureae resemble much the Frigidae except that the 
leaves have more than three leaflets. They are all low plants, 
generally less than 2 cm. high, except P. dissecta, which sometimes 
reaches a height of 3cm. The pubescence is scant, silky, strigos€ 
or hirsute, only in a variety of P. dissecta a little tomentose on the 
lower surface of the leaves, and the plant often becomes glabrous 
and shining in age. The style in all is very slender and filiform, 
fastened near the apex of the achene and generally much longer 
than theachene, Most of the species belonging to this group have 
truly digitate leaves, but in the North American representatives — 
the outer leaflets are often inserted lower down and the leaves be- 
come pinnate with approximate leaflets. | 
