Prairie rose is a high-climbing, trailing, or leaning woody vine. In the open, it is a dense shrub.
Leaves are alternate, feather-compound, leaflets commonly 3 on old stems, on new stems 3 or 5; leaflets lance- to egg-shaped, toothed, tip pointed, lateral leaflets short-stemmed, terminal leaflet long-stemmed. Stipules at leaf bases have smooth margins.
Twigs are flexible, smooth, green or reddish, thorns straw-colored or pale brown, ¼ inch long, often in pairs at the nodes.
Bark on older stems is grayish-brown with scattered thorns.
Flowers late May–June, many-flowered clusters on new stems, large, to 3¼ inches wide, heavily perfumed; petals 5, pink (rarely white); stamens numerous.
Fruits in September, red “hips,” about 3/8 inch long, fleshy, round to broadest above the middle, usually with gland-tipped hairs.
Similar species: Thirteen species in the genus Rosa have been recorded in Missouri. Below are two of the most widespread of these.
Pasture rose (Rosa carolina) is the most common low-growing rose with highly prickly stems (R. setigera has well-spaced thorns). Height, leaflet shape, and prickliness vary. Flowers usually solitary; otherwise very similar to R. setigera (pink, rarely white, very fragrant). Leaves compound with 3, 5, or 7 leaflets. Leaflets round, oblong, or oval, small, finely toothed. The stipules at the base of stem leaves are winged. Look for it in glades, fields, prairies, fencerows, rights-of-way; statewide.
The invasive, nonnative multiflora rose (R. multiflora) has comblike hairs on the stipules at the leaf bases; flowers smaller, in clusters, with white petals, and more leaflets per compound leaf.