2b. Rubus arcticus Linnaeus subsp. acaulis (Michaux) Focke, Biblioth. Bot. 17(Heft 72): 24. 1910.
Dwarf raspberry, ronce acaule
Rubus acaulis Michaux, Fl. Bor.-Amer. 1: 298. 1803; R. arcticus var. acaulis (Michaux) B. Boivin; R. arcticus var. grandiflorus Ledebour
Plants 0.5–2 dm. Stems glabrous or hairy. Leaves usually ternate; petiole glabrous or hairy; central leaflets ovate to obovate, to 6 cm (lateral leaflets shorter), base cuneate, margins dentate to serrate (often doubly), apex usually rounded. Inflorescences: flowers solitary. Pedicels stipitate-glandular. Flowers: sepals caudate, glabrous or hairy, eglandular or glandular; petals pink to rose, oblanceolate to obovate, 15–25 mm, apex slightly to strongly emarginate. 2n = 14, 21.
Flowering May–Aug. Muskegs, boggy woods, fens, bogs, swamps, thickets, moist tundra; 0–3000 m; St. Pierre and Miquelon; Alta., B.C., Man., Nfld. and Labr., N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Colo., Maine, Mich., Minn., Mont., Oreg., Wash., Wyo.
Subspecies acaulis hybridizes with Rubus pubescens (R. ×paracaulis L. H. Bailey [= R. pubescens var. paracaulis (L. H. Bailey) B. Boivin]) in areas of sympatry.