Carolina rose (Rosa carolina) of the Rose (Rosaceae) family occurs in the U.S. from Texas to Nebraska to Minnesota thence east and south to the borders. In Arkansas it occurs throughout the state. The genus name is Latin for “rose.” The specific epithet refers to the type location for the species–i.e., the specimen based on which this species was first described and named was collected in the Carolinas. Other common names include “pasture rose” or “low rose.” Habitats include woods and thickets as well as prairies and glades with various dry to mesic soils. It does well in partial shade or full sun.
This perennial, low-growing deciduous shrub has a tap root and shallow horizontal rhizomes. Plants, 1 to 3 feet tall, have erect woody stems and branches. New branches, from several to 6 inches long, are a light green the first year, become reddish brown the second year, and dark tan in following years. All stems and branches are covered with many fine to slender straight prickles intermixed with a few significantly larger and stouter prickles which occur mostly near leaf nodes. The numerous prickles, set perpendicular to stems and branches, are persistent with the larger ones reaching ½ inch.
Alternate leaves are odd-pinnate-compound generally with five elliptic leaflets; however, three and seven leaflets also occur. Leaflets taper toward their apices and bases. The upper three-fourths of leaflet margins are serrated, with serrations becoming smaller toward the base where they are absent. The hairless (glabrous) leaflets are glossy dark green above and non-glossy lighter green below. Leaves up to 5 inches long, including an inch-long petiole (stalk of leaf), have terminal leaflets up to 1½ inches long, including a ¾ inch petiolule (stalk of leaflet). Lateral leaflets are on very short petiolules. The upper leaflet pair is of similar size as the terminal leaflet while lower pairs decrease in size toward leaf base. Leaf rachis, when viewed from the side, has a smooth arch from the base of petiole to the base of petiolule of the terminal leaflet where a “knee” flexes the terminal leaflet upward. The lower side of rachis is covered with small prickles which continue along lower side of leaflets’ mid-ribs. The upper side of the rachis is grooved. Narrow, elongate stipules, which terminate with acute spreading tips, are attached along the bases of petioles. A single “extra” leaflet may occur at the upper end of a stipule. Margins of stipules are entire or have minute prickles.
The inflorescences occur at the ends of current year’s branches, and typically consist of a single flower, but two flowers may also occur. A calyx consists of five light green, strap-like to narrowly triangular sepals which terminate with long, narrow to leafy tips. Pedicels (flower stalks) are covered by glandular hairs which extend onto the sepals. A prominent ball-shaped, smooth hypanthium (which will be the hip in fruit) is located at the base of the calyx.
Inflorescence occurs in May. Flowers normally are in bloom for only one day, with the blooming period of a colony extending over several weeks. Flowers are two or more inches across with five light to dark pink petals and a wide mass of pistils. Petals are wide, slightly overlapped with a broad gently notched tip. Numerous stamens with white filaments radiate from the base of the pistils so that the showy yellow anthers are spaced a distance out from the pistils. Anthers become brown as flowers mature.
After bloom, the hypanthium develops into a bright red, smooth, fleshy berry-like fruit (hip) that contains about 10 hard achenes (technically the true fruits, each with a single seed within) around a central axis. Hips remain on the shrub into the following spring, unless eaten by wildlife. In spring, remaining hips become dry, eventually deteriorating to release achenes. Mature achenes are somewhat elongated, shiny, smooth and chestnut-brown with two flattened sides and one curved side. Upper ends of achenes are covered with short hairs.
Carolina rose would do well in a garden or naturalized area in loose, dry to moist soils where the plant’s tendency to form colonies may be welcomed. It’s a good choice where soil erosion is an issue. Flowers have a very pleasant rose scent. Once established it will do well in sun and will be drought tolerant. Flowers produce pollen for bees, but do not produce nectar. Spiny Rose Gall Wasps (Diplolepis bicolor) can deposit eggs at base of new branches sometimes causing the plant to produce half-inch galls with several larvae at the center.
Three other native rose species are found in Arkansas; namely, white prairie rose (Rosa foliolosa), uncommon and known only from a couple localities in the Ouachita Mountains; swamp rose (Rosa palustris), which grows in wetlands and is known only from the northeastern corner of the state; and climbing rose (Rosa setigera), which occurs throughout much of the state but less frequently in the West Gulf Coastal and Mississippi Alluvial Plains. At least six non-native species also occur as naturalized in Arkansas. The most widespread and invasive non-native is multiflora rose (Rosa multiflora), which spreads by tip-rooting of stems and by freely seeding from its many white flowers. Carolina rose can be identified by a combination of its short stature, straight prickles, colonial nature, and wide mass of pistils.
Article and photographs by ANPS member Sid Vogelpohl