Potentilla. ] XXVI. ROSACER. 139 
Stock tufted, with long creeping runners rooting at the nodes, as in P. 
yeptans. Leaves pinnate, with numerous oblong, deeply toothed leaflets, 
green or somewhat silky on the upper side, of a shining silvery white 
underneath from the silky down with which they are covered. Peduncles 
long, solitary at the rooting nodes, bearing a single rather large yellow 
flower. | 
Common on roadsides, in stony pastures, and waste places throughout 
Europe, Russian and central Asia, and a great part of North America, ex- 
tending to the Arctic regions, and reappearing in the southern hemisphere. 
Abundant in Britain. FU. summer. 
8. P.rupestris, Linn. (fig. 319). Rock Potentil_—Stock perennial, 
sometimes forming a very short, woody stem, the annual flower-stems 6 to 
10 inches high. Leaves chiefly radical, pinnate; the common stalk rather 
long; the leaflets 5 or rarely 7, ovate, toothed, green, and somewhat 
glutinous. The stem-leaves few and smaller, usually with only 3 leaflets. 
Flowers few, rather large, of a pure white, forming a loose, irregular 
corymb. . | 
In clefts of rocks, in limestone districts, in the mountain-ranges of central 
and southern Europe, and across the whole continent of Asia, extending 
northwards into southern Sweden. In Britain, only in one spot on the 
Breidden hill in Montgomeryshire, except where it may have established 
itself for a time in the neighbourhood of gardens in which it has been cul- 
tivated. Fl. May and June. 
9. P. Comarum, Nestl. (fig. 320). Marsh Potentil.—A perennial, 1 
to 14 feet high, often assuming a bluish-purple colour, glabrous or more or 
less hairy in the upper part; the stems decumbent and rooting at the base. 
Stipules not distinct from the enlarged base of the leafstalk. Leaflets 
mostly 5, shortly pinnate at the end of the stalk, oblong, toothed, nearly 
glabrous above and hoary underneath, or softly hairy on both sides, and 
often near 2 inches long. Flowers in a loose, irregular corymb, of a dingy 
purple; the inner segments of the calyx broad, with long points, the outer 
ones narrow and much smaller, Petals shorter than the calyx. Carpels 
numerous and small, on a somewhat enlarged, rather spongy receptacle, 
on which account this plant is often considered as forming a distinct 
genus, under the name of Comarum. (Comarum palustre, Nest.) 
In marshes, peat-bogs, and wet places, in northern and central Europe, 
Asia, and a portion of North America, penetrating far into the Arctic 
regions. Widely distributed over Britain, but rare in the south of England. 
Ll. summer, 
VIIl. SIBBALDIA. SIBBALDIA. 
Habit and characters of Potentilla, except that the number of stamens 
and carpels is reduced below 10, generally from 5 to 7. The genus consists 
but of very few species, small alpine plants, inhabiting the great mountain- 
ranges both of the new and the old world. 
1, S. procumbens, Linn, (fig. 321). Procumbent Sibbaldia.—The 
perennial stock forms a short dense, spreading tuft. Leafstalk seldom 
above 6 lines long, with 3 obovate or wedge-shaped leaflets, 3-toothed at 
the end, green, and more or less hairy on both sides. Flower-stems } to 
134 inches long, almost leafless, bearing a cyme of small flowers, of which 
