ROSACEAE. 513 



Leaflets 3-9, often resinous, obtuse at base; flowers solitary; sepals erect. 

 Fruit globose or nearly so, 12-15 nim. in diameter. 3. R. Sayi. 

 Fruit ellipsoid or obovoid, 8-10 mm. broad and 15-18 mm. long. 



4. R. Engelma?ini. 

 Leaflets 7-1 1, not resinous, narrowed at base ; flowers corymbed ; sepals 

 spreading. 5. R. Arkansana. 



Infrastipular spines commonly present ; stems prickly. 6. R. Woodsii. 



Sepals deciduous, spreading. 



Leaflets finely serrate; spines stout, recurved. 7. R. Carolina. 



Leaflets coarsely serrate. 



Infrastipular spines nearly straight ; native bushy species. 

 Stems with scattered prickles or naked. 



Leaflets 7-9, shining above ; flowers corymbose; spines stout. 



8. R. lucida. 

 Leaflets 5-7; flowers solitary or few ; spines slender. 9. R. humilis. 

 Stems very densely prickly; flowers usually solitary. 10. R. nitida. 

 Infrastipular spines stout, hooked ; introduced wand-like or climbing species. 

 Leaflets somewhat pubescent beneath, serrate. n. R. canina. 



Leaflets very glandular beneath, doubly serrate. 12. R. rubiginosa. 



1. Rosa setigera Michx. Prairie Rose. Climbing Rose. Michigan Rose. 

 (I. F. f. 1965.) Stems several meters long, armed with scattered curved prickles, 

 not bristly. Petioles, twigs and peduncles often glandular-pubescent; stipules 

 very narrow; leaflets mostly ovate, acute or obtusish at the apex, rounded at the 

 base, 3-7 cm. long, sharply serrate; flowers corymbose, about 6 cm. broad; sepals 

 ovate, acute, at length reflexed and deciduous, glandular; petals rose-color or 

 white ; fruit globose, 8-10 mm. in diameter, more or less glandular. In thickets 

 and on prairies, Ont. to Wis., Kans., W. Va., Fla. and Tex. Escaped from cul- 

 tivation in N. J. and Va. June-July. 



2. Rosa blanda Ait. Smooth or Meadow Rose. (I. F. f. 1966.) Erect, 

 6-12 dm. high, entirely unarmed or with a few straight slender prickles. Leaf- 

 lets 5-7, short-stalked, usually pale beneath, oval or obovate, commonly narrowed 

 at the base. 2-4 cm. long, simply and sharply serrate; flowers pink, sometimes 7 

 cm. broad, corymbose or solitary; sepals lanceolate, acuminate, entire, hispid-pu- 

 bescent; fruit globose or pyriform, glabrous or nearly so, about I cm. in diameter. 

 In moist, rocky places, Newf. to Vt. , N. J., Ont. and 111. June-July. 



3. Rosa Sayi Schwem. Prickly Rose. (I. F. f. 1967.) Bushy, 3-10 

 dm. high, the stems and often the branches densely armed with straight prickles. 

 Stipules mostly broad; leaflets 5-9 (rarely 3), oval or oval-lanceolate, obtuse at the 

 apex, rounded at the base, simply or doubly serrate, often more or less resinous- 

 pubescent, 3-5 cm. long; flowers usually solitary, 6-7 cm. broad; sepals lanceolate, 

 acuminate or sometimes dilated above, entire or few toothed, hispid or glabrous. 

 Anticosti to Minn., the X. W. Terr, and Colo. June-July. 



4. Rosa Engelmanni Wats. Exgelmann's Rose. Like the preceding but 

 low, 2-5 dm. high, very slender and with few branches; leaflets very thin, pale 

 beneath; fruit small, elongated, with an evident neck and more or less conical at 

 the base. In open woods from Mich, to S. Dak... Colo, and Tex. 



5. Rosa Arkansana Porter. Arkansas Rose. (I. F. f. 1968.) Erect, 

 3-6 dm. high. Stems densely prickly with slender bristles; stipules rather narrow; 

 leaflets 7— II, oval or obovate, sessile or nearlv so. obtuse at the apex, narrowed at 

 the base, seldom over 2.5 cm. long, simply and sharply serrate, glabrous, or finely 

 puberulent beneath; flowers corymbose or rarely solitary, about 5 cm. broad; sepals 

 lanceolate, acuminate, sparingly glandular-hispid or glabrous; fruit globose or 

 nearly so, 10—12 mm. in diameter, glabrous. Prairies, Minn, and Iowa to Mont., 

 Tex. and N. Mex. June-July. 



6. Rosa Woodsii Lindl. Woods' Rose. (I. F. f. 1969.) Low, bushy, 3-10 

 dm. high, armed with slender mostly straight spines, or unarmed above. Stipules 

 rather broad, entire; leaflets 5-9, oval or obovate, short-stalked or sessile, obtusish 

 at the apex, narrowed or cuneate at the base. 10-18 mm. long, simply and sharply 

 serrate, somewhat glaucous beneath; flowers 3-5 cm. broad; sepals erect on the 

 fruit; fruit globose or globose-ovoid. 8-10 mm. in diameter, glabrous, sometimes 

 glaucous. Prairies, Minn, to Mo., the X. W. Terr, and N. Mex. June-July. 



7. Rosa Carolina L. Swamp Rose. (I. F. f. 1970.) Pushy, 3-25 dm. high, 



