106 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
acuminate, green, often 2-3-cleft. Basal leaves pinnate, of many leaflets, sparingly strigose- 
ciliate, nearly as long as the stems. Stem leaves much reduced; leaflets divided n arly 
to the base into linear subulate divisions, which therefore look as if verticillate; pedi- 
cels slender, 1-2 cm. long, in fruit abruptly reflexed below the strigose-hirsute hypan- 
thium. Bractlets and sepals lanceolate, acute, the former slightly smaller. Corolla 12- 
18mm. in diameter. Petals obcordate, deeply notched, longer than the sepals. Stamens 
about 20. Achene smooth with a slender filiform nearly terminal style. 
P. millefolia most resembles P. Plattensis, but differs in the long and very narrow 
segments of the leaves, the reflexed fruiting calyx and the longer sepals. The following 
specimens have been examined: 
California: J. G. Lemmon, 1873; 1874; No. 86, 1875 (type), and No. 38; E. L. 
Greene, No. 750, 1876; J. W. Congdon, No. 277, 1880; T. S. Brandegee, 1887 and 1892; 
Baker & Nutting, 1894. 
gi. Potentilla Arizonica Greene. 
Ivesia pinnatifida Wats. Proc. Am. Acad. 20: 364. 1885. Not P. pinnatifida Ta. 
Potentilla Arizonica Greene, Pittonia, 1: 104. 1887. 
InLusTRATIONS: PLATE 45, f. 2; dissection of flower after blooming, f. 3; pistil, f. 4; 
fruiting hypanthium and calyx, f. 5. 
Perennial with a thick woody branched caudex. Stems ascending or erect, a little 
over I dm. high, subscapose, grayish strigose. Leaves nearly all basal, rather irregularly 
pinnate, with 7-12 pairs of leaflets, grayish strigose-hirsute ; leaflets obovate in outline, 
divided to near the midrib into 7-9 linear diverging segments. Stipules brown, adnate 
to the petiole for a long distance, striate. Cyme 5-8-flowered. Hypanthium strigose, in 
fruit 5-8 mi. in diameter; bractlets oblong or lanceolate, a little shorter than the ovate 
sepals. Petals unknown. Stamens 20. 
This was described by Watson from fruiting specimens and referred to Ivesia. These 
fruiting specimens, which are the only ones I have seen, show very plainly that the plant 
is a true Potentilla nearest related to P. pinnatisecta and P. Richardii. It should not be 
placed in Jvesia, even if the latter is regarded as a subgenus of Potentilla, as it has all the 
characters of a true Potentilla. 
Arizona: J. G. Lemmon and wife, 1884 (near Flagstaff). 
92. Potentilla pinnatisecta (Wats.) Aven Nelson. 
Potentilla pinnatisecta Aven Nelson, Wy. Exp. Sta. Bull. 28: 104. 1896. 
Lydb. Bull. Torr. Bot. Club, 23: 432. 
