Greenbrier

Smilax glauca

Greenbrier_Smilax_glauca.jpg

Illustration of greenbrier leaves, flowers, fruits
Greenbrier, Smilax glauca
Paul Nelson
Thorny
Edible
Other Common Name
Catbrier; Cat Greenbrier; Glaucous-Leaved Greenbrier
Family

Smilacaceae (greenbriers)

Description

Greenbrier is a slender, spiny, woody vine climbing by coiled tendrils.

Leaves alternate, simple, 1½–4 inches long, 1¼–3 inches wide, broadly heart-shaped or oval or lance-shaped; margins entire; upper surface dark green, sometimes with lighter blotches; lower surface smooth, conspicuously whitened with a waxy coating or bluish-gray or silvery. There are 3 main veins at the leaf base. Leaf stalk sometimes has a spine on each side at the base. Leaves turn copper-colored in winter, before the leaves drop off.

Stems are slender, climbing by delicate tendrils; tendrils arising in pairs at the base of leaf stalks; young stems smooth, mostly spineless; older stems green to dark brown, smooth; spines sometimes numerous, green to reddish brown or black, about ¼ inch long, straight or slightly curved.

Flowering is in May–June. Flowers are yellowish green, small, smooth; male and female flower clusters on the same plant, arising in the leaf axils of new stem growth; cluster stalk ¼–1¼ inches long and flattened; clusters with 6–12 flowers; petals 6.

Fruits mature September–October. Fruits are shiny black berries, ¼ inch thick, globe-shaped, with a white waxy coating; occur in small, sparse clusters. Seeds 2 or 3 per fruit.

Key Identifiers

 

  • Leaves are strongly glaucus (whitish-waxy) on the undersurface.
  • Stems are round in cross-section, slender, perennial, woody, stout (not easily crushed).
  • Older stems are well-armed with spines.
Size

Stems can be more than 26 feet long.

Habitat and conservation

Occurs in swamps, bottomland forests, mesic upland forests, and banks of streams; also in margins of crop fields, fallow fields, fencerows, roadsides, and moist, disturbed areas. This plant is persistent, forming dense thickets and sometimes becoming weedy in the sandy, open ground of the Missouri Bootheel and on Crowley’s Ridge.

Distribution in Missouri

Scattered mostly in the eastern portion of the Ozarks and in the Mississippi Lowlands.

Status

The greenbrier family is one of the few groups of monocot plants that can have woody stems. (Other monocots include grasses, orchids, lilies, and cattails.) There are 8 species of Smilax in Missouri; 4 are woody, perennial, and bear prickles (the stems are stout and are not easily crushed), and 4 are herbaceous, annual, and lack prickles (you can easily crush the stems, even when dry). If you have a hard time distinguishing between the different Smilax species, don’t feel bad; professional botanists often have trouble, too, especially if specimens are incomplete.

Human connections

The roots of this species and of other prickly stemmed greenbriers are used in making a drink similar to root beer, in which molasses and sassafras are added. An amber-colored sweet jelly can be made by boiling the roots and adding sugar to the liquid. This jelly can be mixed with water to make a sweet drink.

Ecosystem connections

Cardinals, bobwhite, wild turkey, ruffed grouse, and many other birds eat greenbrier fruits. Several mammals eat the fruits, too. The leaves, stems, and fruit are browsed by deer. Many birds and small mammals rely on the impenetrable thickets created by the intertwined mass of prickly greenbriar branches.