MEMOIRS FROM THE DEPARTMENT OP BOTANY OF COLUMBIA UNIVERSITY 195 



or nearly orbicular, all coarsely serrate and incised with ovate mucronulate teeth; stem 

 leaves generally few ; leaflets 2 pairs or ternate and more rhombic. Cyme open, with 

 ascending branches and slender pedicels. Flowers 15-20 mm. in diameter. Hypan- 

 thium more or less glandular- viscid, villous, in fruit not much enlarged, 8-10 mm. in di- 

 ameter. Petals white, drying yellowish, broadly obovate, exceeding the sepals by a third. 

 Bractlets oblong or lanceolate, much shorter than the ovate-lanceolate pointed sepals. 

 Stamens about 25 ; anthers flat, a little cordate at the base. 



This species is exceedingly similar to the European D. rupestris, from which it differs 

 only in the smoother leaves and the longer pubescence of the stem. It differs from the 

 other white-flowered American species in the open cyme, the slender pedicels and the 

 larger petals, which nearly equal in size those of fissa and glutinosa. It grows in the 

 mountains at an altitude of 2000 to 3000 m. The form growing at lower elevations is 

 more leafy, with larger and glabrate leaflets and less viscid stem; this I mistook for P. 

 ladea Greene, but Professor Greene has assured me that it is not that species. In alpine 

 regions it is more glandular viscid and with smaller leaflets. The following specimens 

 have been examined : 



Montana: Rydberg and J. H. Flodman, Long Baldy, Little Belt Mountains, No. 

 598 (type) ; Yogo Baldy, No. 499 : Spanish Basin, Nos. 597 and 600 ; Little Belt Moun- 

 tains, No. 601 (altitudes 6000-8000 feet); R. S. Williams, No. 754, 1888. 



Idaho: B. W. Evermann, No. 363, 1895; J. H. Sandberg, No. 164, 1888; J. B. Lei- 

 berg, 1890. 



California: W. H. Brewer, No. 1714, 1863; Kellogg & Harford, No. 211, 1868-9. 



Washington: W. H. Suksdorf, 1885. 



Yellowstone National Pari: T. H. Burglehaus, 1893. 



Rochj Mountains of British America: Dawson, Nos. 7471, 7870, 18734, 1430, 1881; 

 J. Macoun, No. 10474, 1895. 



PoTENTiLLA LACTEA Greene, Pittonia, 3: 20, 1896 (P. glandulosa var. ladea Greene, 

 Fl. Fran. 65) is still unknown to me. It must be nearly related to the preceding species, 

 but, according to Professor Greene himself, not identical with either of them. The 

 original description drawn partly from fragmentary specimens and mostly from a paint- 

 ing reads as follows: "Delicately and not notably hirsutulous, scarcely glandular, 2 feet 

 high, more loosely cymose branching than the last ; ^ calyx-segments narrow and elon- 

 gated, lanceolate, acuminate, surpassed by the broadly obovate very obtuse white petals; 

 common at middle elevations in the Sierra Nevada, Gal; also appearing to form a part 

 of the Watsonian P. glandidosa var. Nevadensis." 



' i. e., P. Hanseni Greene. 



