Hairs across the abaxial surface of leaf, inflorescences with 1-4 flowers, pedicels erect, 3-5 leaflets, primocanes with stout, broad-based prickles.
A new invasive species for Martha’s Vineyard. Branchlets pilose with hairs of different lengths. Leaf blades pubescent on abaxial midrib. Basal, connate portion of corolla >5 mm long, exserted from calyx. Anthers not surpassing tips of corolla lobes. Panicles compact, 1.5-4 cm long. Pedicels 0.5-2 mm long. Moderately dense pubescence of calyces and pedicels supports ID of var. obtusifolium. (Identified using the key of A Haines, Flora Novae Angliae 2011.)