HORKFUA. ROSACEA. 181 



IVESIA. 



H. caruifolia Rydberg 1. c. Hirsute with long white hairs and more 

 or less glandular: stems ascending, 6-20 inches long: stipules cut into 

 many filiform segments : radical leaves 4-6 inches long, 13-21-foliolate; 

 leaflets broadly cuneiform, 3-6 lines long, deeply cut into 5-9 linear lobes: 

 flowers rather large, in close paniculate cymes : bractlets linear -lanceolate, 

 a little shorter than the acuminate-triangular calyx-lobes: petals suborbic- 

 ular or broadly obovate attenuate below to a claw ; filaments deltoid, a 

 line broad at base : achenes very smooth ovoid, fully a line long. In 

 clayey soil southwestern Oregon. 



He sericata Watson Proc. Am. Acad, xx, 364. White-silky through- 

 out, not at all glandular: stems slender, flexuous, 6-12 inches high: 

 leaves densely white-silky, the numerous leaflets crowded, 2-3 lines long, 

 oblong or obovate, unequally bifid : cymes open and few-flowered; bract- 

 lets linear, nearly equalling the narrowly lanceolate acuminate calyx-lobes; 

 petals narrowly obcordate, white or tinged with pink : filaments short-subu- 

 late : carpels 5. On barren slopes of the Coast Mountains near the Oregon 

 and California boundary. 



H. Howellii Rydberg 1. c. Potentilla Howellii Greene Pitt, i, 104. Pu- 

 bescent with white spreading hairs : stems slender, ascending, 10-20 

 inches long : paniculately branched above : leaves narrow, on short almost 

 filiform petioles ; leaflets 21-31 ,2-3 lines long, broadly cuneiform and deeply 

 2-3-lobed, or narrow and entire : flowers in crowded few-flowered cymes ; 

 bractlets lanceolate, nearly as long as the lanceolate-acuminate calyx-lobes ; 

 petals spatulate, obtuse, 2 lines long : filaments oblong, abruptly acumi- 

 nate. On barren plains, southwestern Oregon. 



H. tridentata Torr. Pac. R. Rep. iv, 81, t. 6. More or less villous 

 with mostly appressed hairs : stems erect from a decumbent base, 10-20 

 inches high : radical leaves 5-9-foliolate ; leaflets cuneate-obovate to nar- 

 rowly oblong, usually 3-toothed at the apex, 3-6 lines long : flowers on 

 slender pedicles, in an open paniculate cyme; bractlets linear, shorter than 

 the lanceolate acuminate lobes of the more or less scarious calyx; petals 

 linear to broadly spatulate, but little longer than the calyx : filaments 

 subulate. On dry hillsides, Southwestern Oregon to California. 

 13 IVESIA T. & G. Bot. Wilkes 288. 



Low herbs with pinnate leaves, numerous small palmately or 

 pedately lobed, often crowded and closely imbricate leaflets and 

 white purple or yellow flowers in cymes. Calyx campanulate or 

 cyathiform at base, 5-]obed with 5 alternate bractlets. Stamens 

 definite, 5, 10, 15, or 20; filaments slender, narrowly subulate or 

 filiform. Carpels few or solitary, upon a small villous recepta- 

 cle; style filiform, sub terminal. 



I. Baileyi Watson Bot. King 90. Yiscidly glandular and villous : stems 

 several, 3-6 inches long, from a thick perennial branching caudex, slender, 

 branching above, exceeding the leaves; leaflets 7-21, broadly ovate or 

 flabelliform, 2-3 lines long, 3-7-toothed : or parted; stipules ovate, entire 

 or 2-3 toothed: flowers on slender pedicels, in a loose open cyme ; calyx 

 concave or broadly turbinate, the ovate-triangular acute lobes but little 

 longer than the oblong obtuse bractlets ; petals yellow or white, spatulate- 

 oblong, not longer than the calyx; stamens 5; carpels 1-5. On cliffs in 

 the mountains of Southeastern Oregon to Nevada and California. 



I. Pickeringii Torr. Bot. Wilkes 288 t. 4. Densely villous with white 

 silky hairs: stems 8-10 inches high : leaflets very numerous, at first closely 

 imbricated, 2-5-lobed or parted or often entire, 1-4 lines long; stems 

 panicled above; cymes densely many- flowered; calyx 2 lines long or less ; 

 bractlets linear; petals yellowish, spatulate, equalling the calyx; stamens 

 20; carpels 4-6. On the Klamath river and southward. 



