432 ROSACEAE 



0. rivale X strictum. With the habit of G. strictum, but differing in the petals, 

 which are golden-yellow, obcordate, clawed at the base and emarginate at the apex, 

 longer than the reflexed sepals; the basal leaves are those of G. rivale. G. aurantiacum 

 Fries. B.C. Alta. n N.Y. 



27. SIEVERSIA Willd. OLD MAN'S WHISKERS. 



Perennial herbs, with rootstocks or suffruticose bases. Basal leaves usually 

 numerous, lyrately or odd-pinnately divided, usually with smaller segments 

 interposed between the larger ones; stem-leaves usually reduced; stipules usually 

 large, adnate to the petioles. Flowers solitary or corymbose-cymose. Hypan- 

 thium turbinate or hemispheric. Bractlets usually present. Sepals 5, valvate. 

 1'ctals 5, white, light yellow, pinkish, or purplish. Stamens many, inserted on 

 a disk in the mouth of the hypanthium. Pistils numerous, inserted on a short 

 carpophore. Styles not articulate or obsoletely so, the lower portion plumose, 

 elongate in fruit, not at all hooked or rarely slightly so, the upper portion glabrous, 

 persistent or withering and then deciduous, but not falling off early at a distinct 

 node. Fruit a hairy achene. Seed erect, basal. [Erythrocoma Greene.] 



Leaflets cuneate, toothed at the apex. 



Hypanthium at least in flower acute at the base; bractlets much exceeding the lance- 

 olate sepals; petals elliptic. 1. S. triflora. 

 Hypanthium in flower rounded or sunken at the base; bractlets about equalling or 



shorter than the ovate or ovate-lanceolate sepals; petals broadly elliptic. 

 Bractlets linear or linear-subulate, equalling the sepals or slightly exceeding them. 



2. S. grisea. 



Bractlets oblong-linear or lanceolate, shorter than the sepals. 3. S. canescens. 



Leaflets dissected at least half way into linear or linear-lanceolate divisions. 



Bractlets longer than the sepals; hypanthium and sepals usually strongly purple- 

 tinged. 4. S. cihata. 

 Bractlets shorter than the sepals; hypanthium and sepals yellowish and only slightly 



purple-tinged. 

 Leaflets, except in depauperate specimens, 2-4 cm. long, ascending, scarcely 



glandular. 5. S. flavula. 



Leaflets less than 1.5 cm. long, spreading, conspicuously glandular-pruinose and 

 hirsute. 6. S. brevifolia. 



1. S. triflora (Pursh) R. Br. Stem finely pilose and somewhat hirsute, 2-4 

 dm. high, cymosely 3-flowered; basal leaves 1-2 dm. long; principal leaflets 7-15, 

 at the apex 2- or 3-cleft less than half their length, finely puberulent; hypanthium 

 densely pilose, more or less turbinate at the base; bractlets linear-subulate, 12- 

 18 mm. long; sepals lanceolate; petals yellowish or flesh-colored. Geum tri- 

 florum Pursh. Erythrocoma triflora, E. cinerascens, and E. affinis Greene. Hills: 

 Newf. N.Y. 111. Neb. Mont. Alta. Plain Submont. My-Jl. 



2. S. grisea (Greene) Rydb. Stem 2-3 dm. high, purple-tinged, pilose 

 throughout; basal leaves 5-15 cm. long; principal leaflets cuneate or obovate- 

 cuneate, 12 cm. long, pilose on both sides, yellowish green, usually 3-cleft to 

 near the middle and again toothed; bractlets linear-subulate, about 1 cm. long; 

 hypanthium hemispheric or slightly sunken at the base, tinged with scarlet or 

 rose; sepals triangular-lanceolate or lance-ovate, petals elliptic or oblong-spatu- 

 late, about equalling the bractlets. Erythrocoma grisea, E. arizonica, E. tri- 

 dentata, and E. aliena Greene. Mountains: Mont. Wash. Ore. N.M.; Chi- 

 huahua. Submont. Mont. My-Jl. 



3. S. canescens (Greene) Rydb. Stem 2-4 dm. high, finely pilose through- 

 out, usually 3-flowered; basal leaves 8-15 cm. long; leaflets obovate-cuneate, 

 1-2.5 cm. long, densely pilose and ciliate on the margins and veins, 2-3-cleft and 

 toothed or sometimes merely 3-5-toothed at the apex; bractlets oblong-linear or 

 lanceolate, 6-8 mm. long; hypanthium hemispheric or sunken at the base; sepals 

 broadly ovate-lanceolate or ovate, acute; petals elliptic or elliptic-obovate, 

 slightly exceeding the sepals. Scarcely distinct from the preceding. E. canescens 

 Greene. Mountains: Wash. Ida. Calif. Submont. 



4. S. ciliata (Pursh) G. Don. Stem 2-5 dm. high, finely pilose and silky- 

 hirsute, cymosely 3-15-flowered; basal leaves 1-2 dm. long; principal leaflets 

 9-19, obovate in outline, finely pilose-puberulent, and more or less densely silky- 

 ciliate on the veins and margins; bractlets linear-subulate; sepals finely pilose, 

 ovate-lanceolate; petals broadly elliptic or oval, flesh-colored or yellowish. 



