84 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
on very slender pedicels, rather large, yellow ; calyx-lobes lanceolate, the accessory lobes (bractlets) 
linear. Stamens 20. Styles filiform, nearly terminal.’”’— Watson, /. ¢. 
Mexico, State of Chihuahua: C. G. Pringle, No. 1494. 1887. 
67. Potentilia Hookeriana [Lehm. 
Potentilla Hookeriana Lehi. Ind. Sem. Hort. Bot. Hamb. 1849: 10. 1849. 
Lehm. Stirp. Pug. 9: 18; Walp. Ann. 2: 509, Lehm. Rev. Pot. 163. 
Wats. Proc. Am. Acad. 8: 554; Macoun, Cat. Can. Pl. 1387; Rydb. Bull. Torr: 
Bot: Club.23':7 302: 
InLustrations: Lehm. Rev. Pot. pl. 55. PLatE 33, f. 1; dissection of flower, f. 2; 
pistil, f. 3; stamen, 7. 4; fruiting hypanthium and calyx, f. 5. 
Stems several from the caudex, 1-2 dim. high, white-tomentose and silky-villous, as- 
cending, few-leaved. Stipules lanceolate, acute. Leayes with petioles 1-2 em. long, ternate 
or occasionally with a pair of small extra leaflets, white on both sides, silky-villous above, 
densely tomentose beneath; leaflets obovate in outline, about 1 em. long, deeply cleft to 
near the midrib into oblong lobes; middle leaflet short-petioled. Flowers in small 
dense cymes, about 8-10 mm. in diameter. Hypanthium densely silky-villous, in fruit 
5 mm. in diameter; bractlets linear, about equalling the lanceolate acute sepals. Petals 
obeordate, generally a little exceeding the sepals. Stamens 20. 
Dr. Watson placed this with P. Pennsylvanica on account of the style; this is gland- 
ular, but scarcely thickened near the base, as it always is in P. Pennsylvanica. In 
habit it comes nearest to P. nivea; and as the style is often glandular in P. vil/osa and 
sometimes in P. nivea, it is better to include P. Hookeriana in this group, with which it 
agrees in other respects. It differs from P. nivea in the more deeply dissected leaves, 
the smaller flowers, the bractlets, which equal the sepals, and a slightly stricter habit. 
It is a very rare plant. The only specimens seen are : 
Saskatchewan: Bourgeau (Palliser Exp.). 1857-8. 
Montana: Wm. M. Canby, No. 103. 1885 (?). 
Alberta: John Macoun, No. 16735. 1897. 
Rocky Mountains: Drummond (Lat. 52° 56’). 
68. Potentilla nivea L. 
Potentilla nwvea L. Sp. Pl. 499. 1758. 
Sp. Pl Hd. 227153 Willd. Sp. Pl 22 1100)" Vali ils Wamrpls 2025. sie ours 
Lam. Ene. Meth. 5: 600; Persoon, Syn. Pl. 2: 56; Nestler, Mon. Pot. 29 and 73; Haller, 
