That looks like kale to me.  Chances are pretty good that if got it in the produce aisle, and it isn’t in the onion family, it should be fine for your buns.  The kale that I get looks like that, very dark green, thick leaves and stems.

Any of the brassicas can give bunnies gas.  This inculdes kale, collards, cabbage, broccolli, cauliflower and brussels sprouts.  I don’t know why the bunny veggie lists almost always say kale is OK but avoid cabbage, maybe the leaves are different somehow.  Genetically it is the same plant, we (humans) have just selectively bred it to produce different things for our needs.

In terms of humans eating it, I think it needs to be shredded and slow cooked, similar to collard greens.  I have never actually made it.

yup thats kale alright!  mmmmm kale.  lol.  it’s pinky’s fav and baby bun likes it too but no more than 3x per week or she gets poopy butt.  i never ate kale before i started making green smoothies.  they’re a great veg… according to nutritiondata.com raw kale “is low in Saturated Fat, and very low in Cholesterol. It is also a good source of Dietary Fiber, Protein, Thiamin, Riboflavin, Folate, Iron, Magnesium and Phosphorus, and a very good source of Vitamin A, Vitamin C, Vitamin K, Vitamin B6, Calcium, Potassium, Copper and Manganese.”  how can you not eat that?  a couple of leaves minus the thick stem tastes yummy blended with water & your fav fruit.

I grew Kale last year, and that’s sort of how young kale looks -like looser curls less stiff leaf. Once it matures it turns that lighter color with very tight curls and stiffer leaf. Either way mine go bonkers for it!!