ROSE FAMILY 437 



Inflorescence racemose; fruit red; leaves, when having more than 3 leaflets, 

 pinnately compound. 

 Plant not at all glandular-hispid; inflorescence with weak prickles, 

 villous. 11. R. melanotrachys. 



Plant more or less glandular-hispid, especially in the inflorescence. 



Sepals narrowly lanceolate, gradually acuminate; leaves glabrate 

 beneath in age. 

 Stem sparingly bristly; leaflets neither strongly phcate nor 



strongly veined. 12. R. perarnoenus. 



Stem densely bristly; leaves strongly plicate and strongly veined. 



13. R. viburnif alius. 

 Sepals ovate or ovate-lanceolate, abruptly acuminate. 



Young stems, petioles, and inflorescence neither densely tomen- 



tose nor puberulent. 14. R. melanolasius. 



Young stems, petioles and inflorescence densely tomentose or 

 puberulent. 15. R. acalyphaceus. 



Carpels coherent to the fleshy receptacle; plant dioecious with decumbent steins 

 and 1-3-foholate green leaves. 16. R. macropetalus. 



1. R. Chamaemorus L. A herbaceous perennial, with creeping rootstock; 

 stem 1-3 dm. high, 1-3-leaved; leaf-blades reniform, with 3-7 rounded lobes, 

 pahnately veined; flowers solitary; petals white, obovate, 8-12 mm. long; stamens 

 numerous, in the pistillate flowers without anthers; fruit at first red, when ripe 

 yellow or golden. Cloud-berry. Baked-apple Berry. Arctic and subarctic 

 sphagnum swamps: Greenl. — N.H. — B.C. — Alaska; Eurasia. Boreal. Jl-Au. 



2. R. pedatus Smith. An xmarmed herbaceous perennial, with flagelliform 

 creeping branches; flowering branches very short, 2-4-leaved; leaflets thin, ir- 

 regularly incised, obovate, or rhombic, 1-5 cm. long; flowers solitary; petals 

 white, obovate-oblong, spreading or reflexed; stamens many; pistils 1-6; fruit 

 purple; drupelets short-stipitate. Woods : n CaUf . — Ida. — Alta. — Yukon — Aiaska. 

 Boreal — Mont. Je-S. 



3. R. acaulis Michx. An unarmed herbaceous, subdioecious perennial, 

 with creeping rootstock; stem 3-12 cm. high, 2-4-leaved; leaflets 3, broadly 

 obovate to flabelliform, unevenly serrate; petals rose-colored, with yellowish 

 claws; fruit red; drupelets 20-30, coherent. Arctic and subarctic swamps and 

 tundras: Lab. — Newf. — Minn. — Alaska. Boreal — Subalp. Je-Au. 



4. R. arcticus L. An unarmed herbaceous perennial, with a rootstock; 

 stem 0.5-2 dm. high, 2-6-leaved, more or less flexuose: leaflets 3, obovate to rhom- 

 bic, coarsely dentate, 1.5-4 cm. long; petals rose-colored, clawless, sometimes 

 denticulate; fruit red, globose; drupelets 20-40, coherent. Bogs: Lab. — Alta.; 

 Eurasia. Boreal — Subalp. Jl-Au. 



5. R. pubescens Raf. An unarmed perennial, with flagelliform, procum- 

 bent shoots, 1-10 dm. long; leaves ternate, rarely quinate; leaflets 3-10 cm. long, 

 green on both sides, sharply and doubly serrate, the lateral ones obliquely ovate, 

 the terminal one rhomboid; petals elliptic or oblanceolate; fruit red, globose; 

 drupelets rather few, large, slightly coherent. R. triflorus Richards. R. ameri- 

 canus (Pers.) Britt. Damp woods and swamps: Newf. — N.J. — la. — Mont. — 

 B.C.; Colo. Boreal—Mont. My-Jl. 



6. R. transmontanus Focke. A mostly herbaceous perennial, with a 

 creeping rootstock; shoots creeping, flagelliform, slightly bristly or glandular- 

 hispid; leaves ternate; leaflets rhombic-ovate, 3-7 cm. long, acute at the base, 

 acuminate at the apex, rather coarsely serrate; inflorescence 1-3-flowered; petals 

 erect, white, oblanceolate, 4 mm. long; pistils 20-50; fruit hemispheric, red. 

 Perhaps a hybrid of R. pubescens with some species of the R. strigosus group. 

 Woods: B.C. Mont. My-Jl. 



7. R. nivalis Dougl. A perennial; stems more or less woody, creeping, 

 terete, puberulent, 3-12 dm. long, sparingly armed with curved or hooked prickles; 

 leaves simple or sometimes ternate, bluish green and shining; blades of the simple 

 leaves 3-6 cm. long, ovate-cordate or rounded-cordate, more or less distinctly 

 3-lobed, dentate; lower leaflets of the ternate leaves obliquely ovate, the terminal 

 one broadly rhombic-ovate, somewhat larger; flowers usually solitary; hjqjan- 

 thium short- turbinate, more or less prickly; petals white, linear-lanceolate, 

 tapering at both ends; pistils few, not all maturing; drupelets pubescent, large, 

 red. Mountains: (?) n CaUf. — Ore. — Ida. — B.C. Mont. — Subalp. Je-Jl. 



