MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 41 



color. Leaflets obovate-cuneate, deeply crenate or cleft with rounded obtuse teeth. 

 Flowers about 7 mm. in diameter, in a branched leafy cyme. Cup sparingly hirsute, in 

 age 7-9 mm. in diameter. Bractlets and sepals oblong-ovate, acute or mucronate, about 

 equal in length. Petals yellow, obovate-cuneate, slightly truncate or emarginate, about 

 equalling or sometimes exceeding the sepals. Stamens 15-20, with short filaments and 

 anthers, the latter with nearly spherical sacs. Pistils very numerous ; style terminal, 

 fusiform. Achenes with a thick corky swelling on the inner side. 



It has been regarded as a form of the European P. supina, and we still find it under 

 that name in most manuals, notwithstanding the fact that the principal distinction has 

 been known since the time of Nuttall. It resembles P. supina in the leaves, which are 

 pinnate with several pairs of leaflets, but differs from it not only in the swollen corky at- 

 tachment of the achene, but also in the stouter and more upright habit, the larger and 

 coarser leaflets and the truly cymose inflorescence. It ranges from New York and On- 

 tario to Washington and New Mexico, and occurs also in Mexico and eastern Asia. 



14. Potentilla Nicolletii (Wats.) Sheldon. 



PotentiUa Nicolletii Sheld. Bull. Geol. and Nat. Hist. Surv. Minn. 7 : 16. In 

 part. 1884. 



Rydberg, Bull. Torr. Bot. Club, 23: 260; Britton & Brown, 111. Fl. 2 : 213. 



P. supina var. Nicolletii Wats. Proc. Am. Acad. 8 : 553. 1873. 



Illustrations : Britton & Brown, 111. Fl. 2 : /. 1926. Plate 6, f. 1 ; dissection of 

 flower, /. 2 ; nearly mature pistil, /. 3 ; stamens, /. 4- ; fruiting hypanthium and calyx, 

 f.5. 



Stems spreading, more branched and more hairy than in P. paradoxa, very slender. 

 Stipules broadly ovate, acute, subentire or sinuate, 5-10 mm. long. Lower leaves pinnate 

 with few leaflets, the upper trifoliolate and much reduced, sparingly hairy and thin. Leaf- 

 lets obovate-cuneate with more acutish teeth than in P. paradoxa, the terminal generally 

 much larger than the lateral ones, 5-25 mm. long. Flowers falsely racemose from the 

 axils of the reduced upper leaves, about 5 mm. in diameter. Cup sparingly hirsute, in 

 fruit very short and broad, about 6 mm. in diameter. Bracts and sepals oblong-ovate, 

 mucronate, subequal, or the bracts a little smaller. Petals obovate-cuneate, about equal- 

 ling the sepals. Stamens 10-15. Pistils numerous ; style terminal, fusiform. Achenes 

 smooth, with a thick corky swelling on the inner side. 



This is much nearer the European P. supina, having the same prostrate habit, small 

 leaflets and falsely racemose inflorescence, but the achenes are of the same structure as in 



