You might not notice a greenbriar until you brush up against its sharp thorns.
Greenbriars, or catbriers (Smilax spp), are green-stemmed, vigorously growing vines that some Lowcountry homeowners spend hours trying to eradicate, often to no avail.
Worldwide there are some 300 kinds, including about 14 in the Carolinas. Some are woody, some herbaceous. The often leathery leaves have various shapes, depending on the species, and some stay green all winter.
Greenbriar produces small flowers in the spring, followed by rubbery berries in the fall.
A vine can ascend to heights of 20 feet or more, aided by tendrils (modified stems) that twist, coil, and attach themselves to other vegetation. In the absence of supports, the plant may form an impenetrable thicket.
And once established in your yard, its sturdy rhizomes can be difficult to dig up.
Though often a nuisance to gardeners, the various native greenbriars are important plants for wildlife.
Thick tangles of the vine provide shelter for animals, and the fruits are eaten by squirrels, rabbits, and many songbirds. Some butterfly and moth caterpillars feed on the leaves, and even humans used to eat young greenbriar leaves, shoots, and tendrils.
Actually, not all greenbriars have those intimidating thorns. Jackson vine (Smilax smallii), for example, is a mostly smooth-stemmed species that’s traditionally used in some parts of the South for Christmas wreaths and garlands.
The underground portions of several other greenbriars, including wild sarsaparilla (Smilax pumila), have been used (as was sassafras) to make a non-alcoholic, root beer-like drink with reputed tonic and medicinal qualities.
Several other thornless species, called carrion flowers, have their tiny blooms arranged in showy, but pungently smelly, clusters that attract certain flies, beetles, and other pollinators.
And preliminary studies of still other greenbriars suggest that extracts of the rhizomes may be useful as anti-cancer agents.
Vicky McMillan, a retired biologist formerly at Colgate University,lives on Hilton Head Island. She can be reached at firstname.lastname@example.org.