518 ROSACEAE 



11. Rubus betulifolius Small. Resembling R. ostryifolius in habit, the foliage gla- 

 brous or nearly so, the stem, branches and petioles armed with flat recurved prickles. Leaves 

 3-foliolate : blades of the leaflets oblong to oval, the terminal one 4-10 cm. long, usually 

 much longer than the lateral ones, all rather coarsely and mostly simply serrate, sometimes 

 slightly puberulent on the veins beneath, smooth and somewliat shining above : flowering 

 branches slightly strigillose when young: corolla 2.5-3 cm. broad : fruit rounded-oblong, 

 10-12 mm. long, black. 



In thickets, Georgia and Alabama. Spring. 



12. Rubus Canad6nsis L. An unarmed or slightly prickly shrub, with ascending 

 or spreading wand-like stems, and branches 1-4 m. long, the foliage glabrous, or the shoots 

 scurfy pubescent. Leaves pedately 5-foliolate or rarely 3-foliolate : blades of the leaflets 

 thin, oval, elliptic or ovate, sometimes obovate, usually glabrous, acuminate, sharply ser- 

 rate : flowers in large leafy-bracted racemes : petals white or pink, 1.5-2.5 cm. long : fruit 

 cylindric-oblong, 1.5-2.5 cm. long, black, juicy. 



In woods and thickets, mountains of New England to Georgia and Alabama. Spring to fall. 



13. Rubus invisus Bailey. A low shrub, with stout ascending or decumbent terete 

 stems armed with straight slightly reflexed prickles. Leaves glabrous or nearly so, those 

 of shoots 5-foliolate, those of flowering branches 3-foliolate : blades of the leaflets broadly 

 ovate to oblong or oval, 2-8 cm. long, acuminate, especially on sterile shoots : corymbs 

 few-flowered, with rather elongated pedicels : sepals with slender tips : fruit globose-oblong, 

 1-1.5 era. long. 



In dry soil. New York to Kansas and Alabama. Summer. 



14. Rubus roribaccus (Bailey) Rydb. A stocky shrub, with terete stems 1-2 m. 

 long, armed with straight weak prickles, the young foliage glandular-villous. Leaves re- 

 sembling those of R. iniisus, but the blades of the leaflets less acuminate, sharply doubly 

 serrate, thinner and lighter green: inflorescence many-flowered, leafy-bracted: sepals 

 with a lanceolate base, foliaceous : corolla 3-5 cm. broad : petals usually broadly obovate : 

 fruit globose-oblong, 1-1.5 cm. long. 



In thickets, Pennsylvania to Virginia and North Carolina. Spring and summer. 



15. Rubus procumbens Muhl. A trailing shrub, with prickle-armed or nearly 



naked stems 1-3 m. long, the foliage thinly pubescent, the branches erect or ascending, 1-3 



dm. tall. Leaves often clustered, with bristly or prickly petioles, 3-7-foliolate : blades of 



the leaflets elliptic-oval, suborbicular or sometimes ovate or cuneate, 2-8 cm. long, sharply 



dentate-serrate and often incised, usually acute or acuminate : flowers solitary or few in 



loo.se racemes : petals white or pink, obovate or cuneate, fully 10 mm. long, rounded or 



retuse at the apex : fruit suborbicular to oval, 2-2.5 cm. long, black, very sweet and juicy. 



[R. Canadensis T. & G., not L.] 



In dry open soil, Ontario to Minnesota, North Carolina, Louisiana and the Indian Territory. 

 Spring. Dewberry. 



16. Rubus rhodophyllus Rydb. Resembling R. procumbens in habit, but with much 

 shorter branches and denser tomentuiose or tomentose pubescence, the stems armed with 

 rather weak slightly recurved prickles flattened only at the base. Leaves 3-foliolate : blades 

 of the leaflets broadly ovate to obovate, rather finely and mostly simply serrate, 1-3 cm. 

 long, generally obtuse, closely tomentuiose beneath, slightly silky above or glabrate at 

 maturity : corolla about 2.5 cm. broad. 



In dry soil or fields, Mississippi and Alabama. Spring. 



17. Rubus subuniflorus Rydb. Resembling R. procumbens but early glabrate or 

 glabrous throughout, with very weak prickles. Branches very slender : flowers mostly 

 solitary on long axillary peduncles at maturity fully as long as the leaves : corolla white, 

 3-4 cm. broad : fruit globose-hemispheric, 1 cm. long or shorter, of few large drupelets. 

 [R. villosus Ait., not Thunb. ] 



In dry or sandy soil, near the coast, Maine to South Carolina. Spring and summer. 



18. Rubus Enslenii Walt. A slender trailing vine, with glabrous foliage, sparingly 

 armed with reflexed prickles. Leaves 2-4 cm. long : blades of the leaflets obovate-cuneate, 

 or the terminal one rhombic-cuneate, crenate-dentate or crenate-serrate above the entire 

 base, usually acute : flowers solitary or 2 together : sepals narrowly ovate, mucronate : 

 corolla 2.5-3 cm. broad : fruit 1-1.5 cm. long, of few drupelets. 



In open woods, Kansas to Alabama and Mississippi. Spring. 



19. Rubus Baileyanus Britton. A prickle-armed shrub, with ascending or trailing 

 stems 3-15 dm. long, the foliage more or less pubescent or glabrate in age. Leaves 3- 

 foliolate, or the upper ones usually simple : blades of the leaflets elliptic to suborbicular 

 varying to ovate or obovate, often acute or acuminate, sharply serrate or incised, commonly 

 rounded or cordate at the base : flowers solitary or few in corymbs : petals white or pink, 



