Stems lax, 50–150 cm, densely to sparsely covered with fine, straight prickles; those at nodes similar. Leaves with 5 to 7, narrowly elliptic leaflets, pubescent on veins beneath,1.5–5 cm long; the rachis glabrate to glandular-pubescent; Flowers mostly solitary; hypanthium glabrous, 3–6 mm long; sepals 15–20 mm long, spreading, dilated at the tip, puberulent, sometimes stipitate-glandular, persistent in fruit; petals 15–30 mm long. Hip globose to pyriform, 1–2 cm long, reddish-purple (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Montana plants are subspecies sayi
(Schwein.) W.H. Lewis.