I have called it Greenbrier or Bull-brier all my life, this large thorny vine has scratched me up many times as I ran through the woods of Kentucky as a boy. I developed a dislike for this tough vine early on in my life. It was easily identified in the winter by its green stem, thorns and shiny green leaves when all the other foliage was brown.
But later in life I have found that the nasty Bull-brier was actually Smilax and it has a value on the dinner plate. Springtime in Florida is when the Smilax starts sending out tender tips as the vine begins to grow. These can be snapped off and prepared like fresh Asparagus. I have a hard time making it back to the house without eating the Smilax raw. The taste reminds me of fresh Asparagus or Green Beans from the garden.
Early settlers called it Sarsaparilla, and in fact Sarsaparilla used to be brewed from the Smilax roots. I have heard that the young roots can cooked in stews, but I have not tried them yet. I have also read that the berries can also be eaten, I may give them a try this fall.
Smilax leaves are green all year and an important food source for deer at the 40 acre woods in Winter when other plants are not growing.
Make sure you properly identify any plant in the wild before you eat it, Smilax is a great plant to learn how to identify.