518 ROSACEAE 
11. Rubus betulifdlius 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 somewhat 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 Canadénsis 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 em. 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 em. long. 
In dry soil, New York to Kansas and Alabama. Summer. 
14. Rubus roribáccus (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. invisus, 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 em. 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 procümbens 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 1n 
loose 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 em. 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 tomentulose 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 Enslénii 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 em. broad: fruit 1-1.5 em. long, of few drupelets. 
In open woods, Kansas to Alabama and Mississippi. Spring. ER 
19. Rubus Baileyànus Britton. A prickle-armed shrub, with ascending or ue 
stems 3-15 dm. long, the foliage more or less pubescent or glabrate in age. d : 
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, common:y 
rounded or cordate at the base: flowers solitary or few in corymbs: petals white or pink, 
