What is this dark-leafed frilly pasture weed that smells faintly of anise/licorice? Is it Perilla?

My neighbor’s horse pasture has a striking weed (or it might be a decorative planting gone feral, it’s very attractive) that I’d like to indentify.

Leaves are dark (almost black, perhaps purple, I have a serious color vision impairment so not sure) and frilly. Stem is mint-family square, but plants have individual root balls, not a creeping mass of stolon-type roots like my mints have. Leaves have a faint anise or licorice odor, and are tender enough to make me view the plant as a potential edible.

My best guess after Googling is something called Perilla, but Perilla pictures are all over the map on color and leaf shape. Plus there seems to be several varieties of Perilla. So I can’t tell.

Anybody recognize it? Thank you!

Sure looks like Perilla to me!

https://www.newson6.com/story/26631508/poisonous-taking-toll-on-oklahoma-cattle

http://oces.okstate.edu/haskell/what-is-perilla-mint/

I've been wondering about this plant too. Or a variation of it that is naturalized here. Mine looks like yours, but smells vaguely like basil. I have used it as a spice in my cooking, in salads. It works great for a mosquito deterrent, rubbed on the skin.

Huh. From Tyler's link, in the comments:

Anna Watts
This "weed" may be toxic to cattle and goats, but it is a God send for humans. As a tea, it is extremely helpful in the fight against colds, flu and other viruses. It is great dried, powdered and added as a spice to cooking. As an infusion/spray/dip, and/or incorporated into soaps, it is fantastic in the fight against fleas, not only repelling them, but killing them . . . it is a natural insecticide that is safe for humans and most pets. When you are outdoors and find yourself battling bugs, just grab a handful, scrunch it up, and rub it all over your exposed skin to keep the pests away. It is a great companion plant for tomatoes, keeping most of the bugs/insects away from them. I let it grow up around my zucchini this year and it was never bothered with squash bugs. Because it has such strong antibacterial properties, killing many food poisoning bacteria, the leaves are often used to as a wrap around sushi. When dining out or eating some place where you are nervous about the possibility of food poisoning, a cup of hot tea made from Perilla Mint following your meal can often ward off an annoying illness afterwards.
It has great cleaning properties, which makes it great for using in soaps. Kills germs and cleans, what more could you ask for from a plant to add into your soaps. It also goes by the name of "Shiso." YES, it should be kept away from cattle, goats, etc, but it should NOT be all killed out. It IS a very VALUABLE plant, not just an ornamental. That is the real reason it was brought over to this country, because it has great value and immigrants didn't want to do without it.

Here is what Eat the Weeds says about it.