2. Rubus arcticus Linnaeus, Sp. Pl. 1: 494. 1753.
Herbs, 0.5–3 dm, unarmed. Stems erect, ˂thin, weak, ± woody basally˃, glabrous or sparsely hairy, eglandular, not pruinose. Leaves deciduous, simple and usually 3-lobed or ternate; stipules ovate to lanceolate, 4–8 mm; blade margins dentate, serrate, or doubly serrate, abaxial surfaces sparsely to moderately pubescent, eglandular. Inflorescences axillary, 1–3-flowered. Pedicels glabrous or sparsely to moderately pubescent, eglandular or stipitate-glandular. Flowers bisexual; petals pink to rose or magenta, obovate to oblanceolate, 8–25 mm; outer filaments dilated basally, inner filiform; ovaries glabrous or sparsely hairy, ˂styles filiform˃. Fruits reddish to dark purple, globose, to 1 cm diam., rarely larger; drupelets (10–)15–30, weakly coherent, separating with torus attached.
Subspecies 3 (3 in the flora): North America, Eurasia.
The type specimen of Rubus alaskensis L. H. Bailey has long glandular hairs on the stems and has unusually large leaflets. It may represent a hybrid between R. arcticus and R. idaeus subsp. strigosus or some other species of Rubus.