MEMOIRS FROM THE DEPARTMENT OF BOTANY OP COLUMBIA UNIVERSITY 117 



ovate,, acuminate, green and more or less toothed with lanceolate teeth. Basal leaves 

 with petioles 10-20 cm. long, irregularly pinnate, silky-villous beneath, especially 

 when young and on the rachis and the veins, more glabrous above; leaflets 4-7 pairs, 

 obovate-oblong, 3-6 cm. long, coarsely serrate, more or less decurrent on the rachis, espe- 

 cially the uppermost, which often are confluent. Stem leaves similar but short-petioled 

 and with fewer leaflets. Bractlets lanceolate, equalling or sometimes even exceeding 

 the sepals. Petals about 8 mm., obcordate, about a fourth longer than the sepals. Sta- 

 Stamens 25. 



It is strange that this strongly marked species should not have been described before 

 1893. It was collected by Hall and Harbour in 1862, Wm. A. Bell in 1867, and G. R 

 Vasey in 1881. The first specimens were included by Dr. Gray in P. Hipjnana. On the 

 label of Bell's specimen is written: "Durand suggests P. rivularis. Gray says no! — 

 perhaps P. campestris." One of Vasey's specimens is labeled Potentilla Thurberi. 



P. ambigens is the tallest of the group, 6-7 dm. high, rather sparingly grayish silky. 

 The leaflets are 3-4 cm. long, coarsely serrate and more or less decurrent on the rachis. 

 The following specimens have been examined': 



Colorado: Hall & Harbour, nos. 158 and 162, 1862 (both only in part); E. L. 

 Greene; Osterhout, 1893. 



Neio Mexico: Wm. A. Bell (Ratan Mountains), 1867 ; G. R. Vasey (Las Vegas), 1867 

 1881 ; E. O. Wooten, no. 468, 1897 (White Mountains). 



104. Potentilla crinita Gray. 



Potentilla crinita Gray, Mem. Am. Acad. 1849: 41. 1849. 



Lehm. Rev. Pot. 63 ; Walp. Ann. 2 : 480. 



Wats. Proc. Am. Acad. 8: 555; Coult. Man. Rocky Mts. 84; Rydb. Bull. Torr. Bot. 

 Club, 24: 1. 



Lllustrations : Lehm. Rev. Pot. pi. 21. Plate 5I^, f. 1 ; dissection of flower, 

 /. 2 ; pistil, /. S ; stamen, /. 4.; fruiting hypanthium and calyx, /. 5. 



Stems several from the rootstock, ascending, 2-3 dm., few-leaved, diffusely few- 

 branched, silky-pilose. Stipules 1-2 cm. long, ovate-lanceolate, acuminate, subentire. 

 Basal leaves many, short-petioled, pinnate, silky-villous (pubescence projecting long out- 

 side the tips of the leaves), nearly smooth on the upper surface; leaflets 5-7 approximate 

 pairs, cuneate, 1.5-2 cm. long, toothed at the apex, generally remaining conduplicate. 

 Stem leaves few, small, only 1 or 2 pairs. Bractlets lanceolate, acute, a little shorter 

 than the ovate-lanceolate acute sepals. Petals obovate, deeply retuse, exceeding the calyx. 



This is similar in habit to P. Breweri, but distinguished by its conduplicate, appressed- 



