There are at least seven species of greenbriar (also called catbriar by some) in Missouri. Several have prickles on their stems, while others do not.
Smilax spp. has a vining growth habit forming dense thickets. Some species of Smilax are found throughout Missouri.
Prickles along the main stem.
Seed of three Smilax species. From left: S. bona-nox, S. herbacea and S. hispida.
Life cycle: perennial.