ROSA 



119 



rounded. Buds small, solitary, sessile, ovoid, with 3 or 4 

 visible scales. Leaf-scars alternate, narrow, straight or slightly 

 curved; bundle-traces 3; stipule-scars none. Fruit a berry-like 

 fleshy receptacle (hifi) enclosing numerous achenes; the sepals, 

 crowning the summit, are quickly deciduous or persistent into 



winter. ^ i.. r + 



Members of this genus are so variable, as a result ot exten- 

 sive cultivation, that the following key should be regarded as high- 

 ly tentative. 



a. Stems climbing, leaning or trailing 



b. Plants of dry clearings or roadsides 



c. Native species 



c. Introduced cultivated plant 



b. Plant of swamp thickets 



a. Stems bushy, erect 



b. Canes densely bristly and acicular- 



prickly 

 b. Canes usually prickly but not densely 



bristly 



c. Stems short, not averaging over 

 0.5 m. tall 



d. Prickles straight, slender 

 d. Prickles thick, more or less 

 curved 



c. Stems taller, 1-2 m. high or 

 more 



d. Sepals deciduous from the 



fruit 

 d. Sepals tardily deciduous, 



persisting into the winter 



1. R. setigera 



2. R. multiflora 



6. R. palustris 



8. R. acicularis 



7. R. Carolina 



5. R. virginiama 



4. R. canina 



3. R. eglanteria 



1. R^ setigera Michx. Prairie Rose. Stems more or less 

 climbingTto 5 m. long, not bristly but armed with thick, nearly 

 straight, scattered prickles; fruit globose, 8-10 mm. in diameter, 

 glandular, the sepals deciduous. Thickets, Florida to Texas, north 

 to New York, Indiana, and Kansas (Fig. 149). 



2. JR. multiflora Thunb. Multiflora Rose . Rambler Rose. 

 Trailing or arching, with long reclining or climbing branches; 



