152 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Bot. Cal. 1: 183; Rothrock in Wheeler’s Exp. 6: 114; Rattan, An. Key W. Coast 
Bot. 52. 
Potentilla Gordonii Greene, Pittonia, 1: 106. 1887. 
Greene, Fl. Fran. 1: 69. 
Inuustrations: Hook. Journ. Bot. 5: pl. 12. Puate 92, f. 7; dissection of flower, 
f. 8; pistil, f. 9; stamen, f. 10; fruiting hypanthium and calyx, f. 11. 
Root thick and deep. Caudex woody, branched, cespitose, covered with the re- 
mains of old leaves. Stem subscapose, minutely glandular-puberulent or glabrous, 1-2 
dm. high, seldom 3 dm. Basal leaves numerous, finely puberulent or glabrate, pinnate ; 
leaflets 10-20 rather approximate pairs, 5-12 mm. long, divided into 3-5 segments or 
again divided. Segments broadly oblong to linear. Stem leaves, if any, very small. 
Cyme capitate. Hypanthium campanulate, 5-4 mm. in diameter, villous-puberulent 
and somewhat glandular, yellowish; bractlets linear, about half the length of the ovate 
sepals. Petals yellow, spatulate or oblanceolate, shorter than the sepals. Stamens 5. 
Pistils generally 1-3, sometimes more. 
It is a very variable species and the most common in the genus, extending from 
Wyoming to Montana, Washington and central California. It differs from all the mem- 
bers of the group in its deeper campanulate hypanthium. 
Horkelia Gordonii alpicola. 
Ivesia alpicola Rydberg ; Howell, Fl. N. W. Am. 1: 182. 1898. 
More cespitose and more glandular, stems less than 1 cm. high; leaflets shorter. 
This plant much resembles L. pygmaea in habit, but lacks the bristle-points of the 
leaves and has always 5 stamens. 
About the same range as the species, but generally grows at greater altitudes. 
Horkelia Gordonii megalopetala. 
Petals large, obcordate, much exceeding the sepals; hypanthium less deep. 
Resembles a low plant of H. Gordonii, but differs in the characters given. It may 
be a good species, but the material known is insufficient. 
California: Bolander (Mt. Dana, type in Herb. Calif. Acad. Sci.). 
44. Horkelia pygmaea (Gray). 
Ivesia pygmaca Gray, Proc. Am. Acad. 6: 531. 1865. 
Wats. King’s Rep. 5: 448. 
Tvesia Gordon var. pygmaca Wats. Bot. Cal. 1: 183. 1876. 
