30 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Draba pringlei Rose, sp. nov. 
Perennial from a much-branched caudex, the lower parts covered with old leaf 
bases; basal leaves thin, 2 cm. long, spatulate, tapering at base into a bre mad petiole, 
the margin ciliate, the two surfaces smooth or with afew hairs cither simple or 
stellate; branches about 1 dm. high, nearly naked below, somewhat subdivided 
above; spikes short and compact; pedicels spreading, 5 mm. long, stellate-pubescent; 
petals (at least in old specimens) white; pods ovate, of a deep bluish-green color, 
4mm, long; style very short; ovules about 6 in each cell. 
Collected by C. G. Pringle on the colder slopes within the crater of the Nevado de 
Toluca, altitude 4,080 meters, September 1, 1892 (no. 4248), It was distributed as 
“Draba jorullensis var.,”? but it hardly answers to that species. Here also seems to 
belong the plant described by Mr. Hemsley in the Biologia@ as D. tolucensis, as it 
agrees with mine in color of flowers, and in its short style, hairy pods, ete. 
The true D. tolucensis was found on the low hills about Toluca (altitude 2,400 
meters) and must be very different from this species, which comes from the top of 
Nevado de Toluca. 
ROSACEAE. 
TWO NEW SPECIES OF POTENTILLA. 
Potentilla madrensis Rose, sp. nov. Puare ITT, 
Stems froma thick root, branching at base, ascending 2 to 4 dm. long, glabrous 
below, somewhat villous and glandular-pubescent above, leaves mostly basal and 
long-petioled; stipules small; leaflets 3, glabrous and green on both sides, rounded 
at apex, crenately toothed, 20 to 25 mm, long, obovate to oblong; sepals ovate, acute; 
bracts linear; petals purplish, longer than the sepals. 
Collected by J. N. Rose near Santa Gertrudis, Tepic, August 8, 1897 (no, 2096). 
Nearest P. thurberi, but very different in habit, number of leaflets, ete. 
EXPLANATION OF PLATE II.—Plant, natural size, 
Potentilla rydbergiana Rose, sp. nov. Puare TV. 
Stems from a thick, much-branched caudex, villous-pubescent, the parts above 
ground usually simple and bearing a single terminal flower; basal leaves digitately 
foliate; leaflets 5, obovate, 1 to 2 em. long, with a few coarse obtuse serrations, gla- 
brous above, with a few long hairs beneath; stipules lanceolate, entire; petiole as 
long as or longer than the leaflets; flowering stems slender, ascending, | dim. or less 
long, bearing | to 4 much reduced leaves; calyx lobes ovate and acute; bractlets 
somewhat shorter and broader with the apex rounded; petals bright vellow, 1 em, 
long, retuse. 
Jommon on rocks on the high mountains above Pachuca, [lidalgo. 
Collected by C. G. Pringle, August 3, 1898 (no. 7646, type), and July 21, 101 
(no, 8549), and by J. N. Rose, July 21, 1901 (no. 5607). 
This species has much the habit of 2. ranunculvides, but has fewer and different 
flowers. 
The specific name is given in honor of Dr. P. A. Rydberg, who has monographed 
the genus. 
EXPLANATION OF PLATE IV.—Plant, natural size, 
« Biologia Centrali-Americana 2: 34. 
