98 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Potentilla Pennsylvanica arachnoidea Lehm. 
Potentilla Pennsylvanica arachnoidea Lehm. Stirp. Pug. 9: 41. 1851. 
Rev. Pot. 59; Walp. Ann. 2: 479; Rydberg, Bull. Torr. Bot. Club, 23: 264. 
Potentilla arachnoidea Doug]. ex Lehm. Rev. Pot. 59. 1856. 
Potentilla Pennsylvanica conferta Gray, Mem. Am. Acad. 1849: 42. 1849. 
Plant in every part smaller; segments short ; stem arachnoid-pubescent. Colorado, 
Utah and New Mexico. Specimens seen: 
New 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, 1878; C. C. Parry, No. 216, 1861; 
E. L. Greene, 1870; A. Eastwood, 1892. 
Arizona: E. Palmer. 1877. 
79. Potentilla pseudosericea. 
Potentilla holosericea Nutt. MS. Not Griseb. 
InuustRations: PLate 36, f. 1; dissection of flower, f. 2; stamen, f. 3; pistil, f. 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 hirsute 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. 
Rocky Mountains: Nuttall; Fremont, No. 218, 1845-7. P 
P. holosericea Nutt. is cited as a synonym under P. Pennsylvanica strigosa 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. Watson included Shockley’s specimens in P. Hookeriana, 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. 
