526 KOSACEAE 



Stamens 4, or numerous : filaments elongated. Pistils solitary or 2-3, included : style 

 filiform : stigma brush-like. Ovule solitary, pendulous. Achenes mostly solitary, leathery, 

 included in the dry angled or variously roughened hypanthium. 



1. Sanguisorba Canad6nsis L. Perennial, glabrous or sparingly pubescent. Stems 

 3-18 dm. tall, simple or somewhat branched above : leaf-blades pinnate, those on the lower 

 part of the stem 2-6 dm. long, long-petioled with 7-15 leaflets, the upper ones gradually 

 reduced ; stipules leaf-like, inequilateral : blades of the leaflets oblong, varying to ovate- 

 oblong, or oblong-lanceolate, 1.5-8 cm. long, sharply serrate, rounded or cordate at the 

 base, petioluled : spikes cylindric, 3-15 cm. long : calyx corolloid, white, 3-4 mm. broad : 

 sepals oblong or cuneate, acute or mucronate at the apex, spreading : filaments club-shaped. 

 [Poterium Canadense (L. ) A. Gray.] 



In swamps and low grounds, Newfoundland to Michigan and Georgia. Summer and fall. 



20. ROSA L. 



Usually prickly shrubs, with erect trailing or climbing stems. Leaves alternate : 

 blades unequally pinnate or rarely 2-foliolate : stipules adnate to the petioles. Flowers 

 solitary or in corymbs, showy, white, pink, yellow or red, fragrant. Hypanthium accres- 

 cent, urn-shaped. Sepals usually 5, imbricated, sometimes leaf -like, deciduous or persistent- 

 Petals usually 5, spreading, deciduous. Stamens numerous, inserted near the edge of the 

 disk : filaments filiform. Pistils numerous, distinct, sessile at the base of the hypanthium : 

 styles lateral, distinct or united above. Ovule solitary, pendulous. Achenes numerous, 

 corky to bony in texture, included in the berry-like accrescent hypanthium. ROSE. 



Styles cohering and forming a column, exserted. 1. R. setigera. 



Styles distinct, included. 

 Sepals persistent. 



Hypanthium densely silky, subtended by an involucre of bracts : sepals 



merely acuminate. 2. R. brncteata. 



Hypanthium glabrous or nearly so, not subtended by bracts : sepals with 



somewhat dilated tips. 

 Infrastipular spines usually wanting. 



Leaflets 3-9, often resinous, the blades obtuse at the base : flowers soli- 

 tary : sepals erect. 3. R. Engelmannii,. 

 Leaflets 7-11, not resinous, the blades narrowed at the base: flowers 



corymbed : sepals spreading. 4. R. Arkansana. 



Infrastipular spines present. 5. R. Woodsii. 



Sepals deciduous. 



Deciduous-leaved : leaflets normally 5-13 : stems erect or ascending : hypan- 

 thium often pubescent or glandular. 

 Leaflets with serrulate or finely serrate blades. 



Blades of the leaflets lanceolate, leathery. 6. R. lancifolia. 



Blades of the leaflets elliptic to oblanceolate, membranous. 7. -R. Carolina. 



Leaflets with coarsely serrate blades. 

 Fruit subglobose. 



Leaflets 7-11 : hypanthium hispid. 8. R.foliosa. 



Leaflets 5-7 : hypanthium glandular-pubescent. 9. R. humilis. 



Fruit oval to narrowly ovoid. 



Blades of the leaflets doubly serrate. 10. R. rubiginosa. 



Blades of the leaflets simply serrate. 11. R. comma. 



Evergreen : leaflets normally 3 : stems climbing or trailing : hypanthium 



spinescent. 12. R. Cherokeensis. 



1. Rosa setigera Michx. A climbing or reclining shrub, with glabrous or glandular- 

 pubescent young foliage. Stems 2-5 m. long, armed with recurved prickles : leaves 5-10 

 cm. long ; leaflets 3-5, the blades elliptic or oval, varying to ovate or obovate, 2-8 cm. 

 long, acute or somewhat acuminate, serrate, often lustrous above : flowers showy, a few in 

 terminal corymbs : hypanthium glandular-pubescent, often glaucous : sepals lanceolate, 

 acuminate, reflexed at maturity, deciduous : corolla red, 4-6 cm. broad : petals obcordate : 

 styles cohering : fruit subglobose, 5-10 mm. in diameter, red. 



In thickets and low ground, Ontario to Wisconsin, West Virginia, Florida and Texas. Spring and 

 ummer. PRAIRIE OR CLIMBING ROSE. 



2. Rosa bracteata Wendl. An evergreen spreading shrub, with deep green foliage. 

 Stems and branches diffuse, 2-6 m. long, armed with recurved prickles : leaves numerous, 

 3-6 cm. long ; leaflets 5-11, the blades leathery, obovate, cuneate or oval, 1-2 cm. long, 

 retuse, truncate or apiculate at the apex, serrate, lustrous above, glabrous or minutely 

 pubescent beneath : flowers showy, solitary or a few together : sepals elliptic or triangular- 

 lanceolate, acuminate, reflexed at maturity: corolla cream-colored or yellow, 4-8 cm. 

 broad : petals retuse or notched at the apex : styles distinct : fruit 1.5-2 cm. thick. 



In waste places or in pine woods, Virginia to Florida and Mississippi. Spring Jand summer. 

 Naturalized from China. 



3. Rosa Engelmannii S. Wats. A bushy shrub 2-5 dm. tall. Stems very slender, 



