Part? 3, 1908] ROSACEAE 289 
18. Ivesia Gordonii (Hook.) T. & G. in Newb. Pacif. R. R. 
Rep. 6°: 72. 1857. 
Horkelia Gordonti Hook. Jour. Bot. & Kew Misc. 5: 341. 1853. 
Potentilla Gordonii Greene, Pittonia 1: 106. 1887. 
fvesia alpicola Howell, Fl. NW, Am. 1: 182. 1898. 
Horkelia Gordonii alpicola Rydb. Mem, Dep. Bot. Columbia Univ, 2: 152. 1898. 
Perennial, with a thick and deep root, and short, woody, cespitose caudex, covered 
with the remains of old leaves; stem subscapose, minutely glandular-puberulent or gla- 
brous, 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, 3-4 mm. in diameter, villous-puberulent and somewhat 
glandular, yellowish; bractlets linear, about half the length of the ovate sepals, which 
are about 5 mm. long; petals yellow, spatulate or oblanceolate, shorter than the sepals; 
stamens 3; pistils generally 1-3, sometimes more. 
TYPE LOCALITY: Upper Platte River. 
DISTRIBUTION : Mountains from Washington to California, Colorado, and Montana. 
f ry : Jour. Bot. & Kew Misc. 5: pf. 12; Mem. Dep. Bot. Columbia Univ. 2: p/. 92, 
19. Ivesia megalopetala Rydberg. 
Horkelia Gordonii megalopetala Rydb. Mem. Dep. Bot. Columbia Univ. 2: 152. 1898. 
Perennial, with a thick taproot and a short cespitose almost pulvinate caudex ; stem scapi- 
form, usually less than 1 dm. high ; basal leaves numerous, 3-5 cm. long, glandular-puberu- 
lent, pinnate with numerous small crowded leaflets; leaflets 2-4 mm. long, cleft to near 
the base into spatulate divisions; stem-leaves very small or none; cyme subcapitate; 
hypanthium glandular-puberulent, cupulate, 3-4 mm. wide; bractlets oblong, half as long 
as the triangular-lanceolate sepals, which are about 2 mm. long; petals obovate, longer 
than the sepals; stamens 5; filaments filiform. 
TYPE LOCALITY: Mount Dana, California. 
DISTRIBUTION: Sierra Nevada and Mt. Eddy, California. 
20. Ivesia pygmaea A. Gray, Proc. Am. Acad. 6: 531. 1865. 
Ivesia Gordonii pygmaea S. Wats. Bot. Calif. 1: 183. 1876. 
Potentilla decipiens Greene, Pittonia 1: 106, as to synonyms. 1887. Not P. decipiens Jordan. 
Horkelia pygmaea Rydb. Mem. Dep. Bot. Columbia Univ. 2: 152. 1898. 
Perennial, with a deep perennial root and closely cespitose caudex, densely covered 
with remains of old leaves; stem scapose, 4-7 cm. long, finely glandular-puberulent and 
sometimes with a few longer hairs; basal leaves very numerous, 2-5 cm. long, finely 
glandular-puberulent with numerous, minute, very densely crowded and imbricate leaf- 
lets, which are 1-2 mm. long, divided to the base into oblong or oval thick segments 
tipped with bristles; cyme subcapitate, or in age somewhat corymbose; hypanthium about 
4 mm. in diameter, saucer-shaped, glandular-hirsute with a rather conspicuous disk ; bract- 
lets oblong, about two-thirds as long as the broadly ovate sepals ; petals obovate, a little 
exceeding the sepals; stamens 5-10. 
TYPE LOCALITY : Sierra Nevada, California. 
DISTRIBUTION: Sierra Nevada of California and Nevada. 
ILLUSTRATION: Mem. Dep. Bot. Columbia Univ. 2: pl. 93, f. 1-7. 
21. Ivesia Shockleyi S. Wats. Proc. Am. Acad. 
23: 263. 1888. 
Potentilla decipiens Greene, Pittonia 1: 106, excluding synonyms. 1887, Not P. decipiens Jordan. 
Potentilla nubigena Greene, Erythea3: 36. 1895. _ . : 
Horkelia Shockleyi Rydb. Mem. Dep. Bot, Columbia Univ. 2: 153. 1898. 
Perennial, with a deep woody root, and densely cespitose caudex, covered with the 
remains of old leaves; stem subscapose, densely glandular, 2-5 cm. high; basal leaves 
very numerous, 2-4 cm. long, densely glandular, pinnate, with about a dozen pairs of 
