98 



MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 



Potentilla Pennsylvanica arachnoidea Lehm. 



PotnifiUa Penn.vjlvauica arachnoidea Lehm. Stirp. Pug. 9 : 41. 1851. 



Rev. Pot. 59 ; Walp. Ann. 2 : 479 ; Rydberg, Bull. Torr. Bot. Club, 23 : 264. 



Poteritilla arachnoidea Dougl. ex Lehm. Rev. Pot. 59. 1856. 



PoientiUa Pennsijlvcmica confcrta Gray, 31em. Am. Acad. 1849 : 42. 1849. 



Plant in every part smaller; segments short ; stem arachnoid-pubescent. Colorado, 

 Utah and New ^Mexico. Specimens seen : 



Neiv Mexico : A. Fendler, No. 202, 1847 (in part) ; E. O. Wooton, No. 408, 1892. 



Utah L. F. Ward, 1875 ; M. E. Jones, No. 5673, 1894. 



Colorado: G. Engelmann, 1874; J. M. Coulter, 1873; C. C. Parry, No. 216, 1861; 

 E. L. Greene, 1870; A. Eastwood, 1892. 



Arizona : E. Palmer. 1877. 



7g. Potentilla pseudosericea. 



Potentilla holoxericea. Nutt. MS. Not Griseb. 



Illusteatioxs : Plate 36, f. 1; dissection of flower, /. 2; stamen, /. 3; pistil, /. 4.; 

 fruiting hypanthium and calyx, f. 5. 



Cespitose; stems several from the caudex, ascending or decumbent, 5-10 cm, high, 

 few-leaved, grayish silky. Lower stipules brown and scarious, covering the caudex ; upper 

 ones small, 5 mm. long, ovate, silky. Leaves with rather short petioles, pinnate with 

 2-4 pairs of approximate leaflets, grayish silky or hii'sute above, white-tomentose and 

 silky beneath ; leaflets 1-2 cm. long, obovate in outline, divided to near the middle into 

 linear obtuse segments. Cyme few-flowered. Hypanthium grayish silky, in fruit about 

 5 mm. in diameter ; bractlets oblong, shorter than the ovate or ovate-lanceolate sepals, 

 Petals obovate, about equalling the sepals. 



Nevada: Shockley, No. 592, 1888. 



Roclnj Mountains : Nuttall; Fremont, No. 218, 1S45-7. 



P. holosericea Nutt. is cited as a synonym under P. Pennsijlrauica sirigosa by Torrey 

 and Gray, but Nuttall's specimens show that it is a species very nearly related to P. bi- 

 pinnatifida. Nuttall's specimens, as well as Fremont's, may be taken for depauperate 

 forms of that species, while Shockley's much resemble in habit, leaves and pubescence 

 the Siberian P. sericea, the petals of which, however, are nearly twice as long as the nar- 

 row sepals. Dr. AVatson included Sliockley's specimens in P. Hoejkcrieina, which it resem- 

 bles in pubescence and the form of the segments, but the sepals of that species are much 

 narrower and the leaves ternate. 



