Definitely a preferred deer browse in my North Florida area, and that's saying something as in the springtime here, which starts as early as February, just about EVERYTHING that grows is as green as Ireland.
That, and it's not just edible for deer... from what I've read all smilax variants are non-toxic, and if you can beat the deer to them the tender shoots and tender leaves eat just fine sauteed with some seasonings for taste. You can even safely eat them raw... just not a lot of taste to them, but that said nothing offensive tasting about them either.
I've had them mixed in a couple of omelets over the past few weeks after sauteing them with just bit of seasoning to give them more flavor.

SHTF, I'm going to be REALLY happy to have them around.
Not a video from my own channel, but one speaking to the edibility.... and tons of additional videos on YouTube with folks gathering it / cooking it. Really easy to gather the tender shoots, as if you pull from close to the end of the shoot it will snap cleanly at whatever point the shoot goes from tender to tougher.