This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
?R. villosus Ait. Hort. Kew. 2: 210. 1789. Not Thunb. Rubus procumbens Muhl, Muhl. Cat. 50. 1813. R. canadensis invisus Bailey, Am. Gard. 12: 83. 1891. R. canadensis roribaccus Bailey, Am. Gard. 11: 642. 1890.
Trailing, shrubby, stem often several feet long, armed with scattered prickles or nearly naked. Branches erect or ascending, 4'-12' long, more or less pubescent, sometimes prickly, sometimes slightly glandular; leaves petioled, 3-7-foliolate; leaflets ovate, oval or ovate-lanceolate, thin, deciduous, acute or sometimes obtusish at the apex, rounded or narrowed at the base, sharply dentate-serrate, usually sparingly pubescent; flowers terminal, few and racemose, or sometimes solitary, white, about 1' broad; peduncles leafy; sepals shorter than or exceeding the petals; fruit black, delicious, often 1' long.
In dry soil, Newfoundland(?), Ontario to Lake Superior, south to Virginia. Louisiana and Oklahoma. Creeping blackberry. April-May. Fruit ripe June-July. Referred in our first edition, following previous authors, to Rubus canadensis L., long misunderstood Rubus Ensleni Tratt., of the Southern States, differing by crenate leaflets, is doubtfully recorded as far north as Kansas.
Rubus trivalis Michx. Fl. Bor. Am. 1: 296. 1803.
Stem trailing or procumbent, several feet long, beset with stout hooked prickles, and sometimes bristly. Branches erect, 3'-9' high, prickly and usually pubescent or setose; leaves petioled, 3-foliolate (rarely 5-foliolate); leaflets oval, or sometimes ovate-lanceolate, coriaceous, evergreen, glabrous or very nearly so, acute or obtusish at the apex, narrowed or rounded at the base, sharply serrate; peduncles terminal, prickly, 1-5-flowered; flowers often 1' broad, white; petals much exceeding the reflexed sepals; fruit black, often 1' long, sweet.
In dry sandy soil, Virginia to Florida, west to Texas. Called also southern dewberry. March-May.
Rubus rubrisčtus Rydb., ranging from Louisiana northward into Missouri, differs in being copiously glandular-pubescent, with somewhat smaller flowers.
Rubus hispidus L. Sp. Pl. 493. 1753.
Rubus obovalis Michx. Fl. Bor. Am. 1: 298. 1803.
Stems slender, slightly woody, creeping, more or less densely beset with weak, retrorse bristles. Branches erect or ascending, 4'-12' long, naked, or with a few scattered prickles; leaves petioled, 3-foliolate or rarely 5-foliolate; leaflets obovate, obtuse, thick, persistent, somewhat shining above, narrowed at the base, 1/2'-1 1/2' long, sharply serrate above the middle; peduncles terminal or axillary, nearly or quite leafless; flowers racemose, white, 6"-8" broad; petals exceeding the sepals; fruit reddish, or nearly black when ripe, sour, usually less than Ĩ long, composed of few drupelets.
In swamps or low grounds, rarely in dry soil, Nova Scotia to Ontario and Minnesota, south to Georgia and Kansas. Ascends to 3500 ft. in North Carolina. Leaves sometimes persistent into the winter. Leaflets of sterile shoots sometimes 2'-3' long. June-July.