Smooth Carrion Flower
Smilax herbacea
Greenbrier family (Smilacaceae)

Description: This climbing non-woody vine is a herbaceous perennial up to 8' long that branches occasionally. The light green to purple stems are terete, slightly speckled, glabrous, and often glaucous. Alternate leaves up to 3" long and 2" across occur at intervals along each stem; they are ovate-oval to broadly ovate-lanceolate in shape, smooth along their margins, and parallel-veined. The upper surfaces of the leaves are medium green and glabrous, while their lower surfaces are pale green and hairless. There are no hairs along the raised veins on the leaf undersides. The petioles of the leaves are up to 1" long, light green, and hairless. At the base of most petioles, there is a pair of tendrils that can cling to adjacent vegetation or objects for support. At the base of each stem on the vine, there is an appressed to slightly spreading sheath that is usually bladeless.

Individual umbels of flowers are produced from the axils of the middle to upper leaves of each mature vine. Each umbel is connected to the stem by a long stout peduncle about 4-10" long. The peduncles are 4-8 times longer than the petioles of adjacent leaves; they are similar in appearance to the stems. Individual umbels are about 1–3" across, consisting of 20-120 flowers on slender pedicels; when fully developed, they are globoid in shape. Like other species in this genus, Smooth Carrion Flower is dioecious; some vines produce only staminate (male) flowers, while other vines produce only pistillate (female) flowers. The green to yellowish green staminate flowers are individually about " across, consisting of 6 lanceolate tepals and 6 stamens with white anthers. The green to yellowish green pistillate flowers are individually about " across, consisting of 6 lanceolate tepals and a pistil with 3 flattened stigmata. The tepals of both kinds of flowers are often recurved. The blooming period occurs from late spring to early summer and lasts about 3 weeks. The flowers often have a carrion-like scent, but its presence and strength varies with the local ecotype. Staminate flowers wither away after blooming, while pistillate flowers are replaced by globoid fleshy berries. Individual berries are about " across and contain about 3-5 seeds; they are dark blue and glaucous at maturity. At the end of the growing season, the entire vine dies down to the ground.

Cultivation: Smooth Carrion Flower prefers full or partial sun and more or less mesic conditions. It flourishes in different kinds of soil, including those that are rocky or loamy. In a shady situation, this vine may fail to produce flowers.

Range & Habitat: According to official records, Smooth Carrion Flower is rare in Illinois. However, in neighboring states this vine has been found in many counties and it is regarded as more common. It is possible that some records of Smilax lasioneura (Common Carrion Flower) in Illinois are based on misidentifications and it was Smooth Carrion Flower that was observed. These two species are very similar in appearance and easily confused. Habitats of the native Smooth Carrion Flower include savannas, thickets, prairies, rocky upland woodlands, woodland openings, woodland borders, and fence rows. Occasional wildfires appear to be beneficial in managing populations of this species.

Faunal Associations: The flowers are pollinated primarily by small bees, miscellaneous flies, and beetles. Fly visitors include Flesh flies, Blow flies, Muscid flies, Syrphid flies, mosquitoes, and other species. The bees suck nectar or collect pollen, while the flies and beetles suck nectar or feed on pollen. The butterfly Megisto cymela (Little Wood Satyr) has been observed sucking nectar from Carrion Flower as well. Insects that feed on the foliage of Smilax spp. (whether Greenbriers or Carrion Flowers) include the flea beetle Pachyonychus paradoxus, the thrips Ctenothrips bridwelli, and the caterpillars of several moths, including Acrolepiopsis incertella (Carrion Flower Moth), Phosphila miselioides (Spotted Phosphila), Phosphila turbulenta (Turbulent Phosphila), and Phyprosopus callitrichoides (Curve-Lined Owlet). In addition to these species, the caterpillars of Papaipema unimoda (Meadow Rue Borer Moth) sometimes bore into the stems of Carrion Flowers. The berries of Smilax spp. are eaten by some upland gamebirds and songbirds (see the Bird Table); the Ruffed Grouse and Wild Turkey also eat the young leaves and buds of these vines. The berries are a minor source of food to some mammals: this includes the Black Bear, Opossum, Raccoon, Fox Squirrel, and Gray Squirrel. The leaves and stems are browsed by the White-Tailed Deer and Cottontail Rabbit.

Photographic Location: The Loda Cemetery Prairie in the southwest corner of Iroquois County, Illinois.

Comments: Species in the Smilax genus fall into two large groups: woody vines with prickles or bristles (Green Briers, Catbriers) and non-woody vines that are devoid of prickles or bristles (Carrion Flowers). In Illinois, there are 5 species of Carrion Flower that are currently recognized; some of these species were regarded as mere varieties of Smilax herbacea in the past. Smooth Carrion Flower can be distinguished from similar species using one or more of the following criteria: 1) the undersides of its leaves are pale green and totally hairless, 2) its umbel-bearing peduncles are at least 4 times longer than the petioles of adjacent leaves, and 3) it is a climbing or sprawling vine with numerous tendrils. The very similar Smilax lasioneura (Common Carrion Flower) has fine hairs along the veins of its leaf undersides (and sometimes between the veins as well) while its peduncles are less than 4 times the length of the petioles of the adjacent leaves. Another similar species, Smilax pulverulenta (Powdery Carrion Flower), has leaf undersides that are medium green and it also has fine hairs along its veins. The remaining Carrion Flowers in Illinois are shorter vines with an upright habit of growth and they have much fewer, if any, tendrils.