HORKEMA. ROSACES. 181 



IVESIA. 



H. carnifolia 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 rathe/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. 



H* 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. PotentUla 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 "21-3 1,2-3 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 spa tulate, obtuse, 2 lines long: filaments oblong, abruptly acumi- 

 nate. On barren plains, southwestern Oregon. 



H. tridentata Torr. Pac. R. Rep. iv, 84, 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 

 <iyathiform at base, 5-lobed 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, subterminal. 



I. Baileyl 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. 



