>>a beardie would like more variety
I'm sure some beardie's would like more variety. Some, it seems, could really care less. ;D Our Oolong gets a pretty wide variety of greens, veggies, & the occaisional fruit, but he rarely eats any of it. His favourite non-live food is Rep-Cal pellets (only the green ones, though).
Honestly, as many others have said, beautifuldragons.com has a very, very useful list of foods & their relative nutritional value for beardies:
home.comcast.net/~holachapulin/Nutrition.html
As for Littleherper's specific question:
Kale is a good green fed occaisionally ("High vit. A, moderate oxalates, goitrogens" ), collards are wonderful ("Great staple, high calcium, moderate goitrogens" ) ... romaine lettuce is not so great ("Poor nutritional value, high vit. A, high oxalates" ). If those are the only 3 choices in your area, I imagine your best bet would be to feed collards as a staple, w/ kale a few times a week & romaine as a treat.
Personally, if I can't make a trip to the local health food store (which is where most of the good veggies are), Oolong gets fed primarily organic Spring Mix (or "Baby Greens", depending on the store & the individual brands). I've heard horrible things about pesticides & whatnot in non-organic salad mixes, so I pay the extra dollar or so for organic. I know, too, that spring mix gets a bad rap among a lot of beardie owners/breeders, but I don't think that that's entirely deserved. I do think that beardie owners who go the spring mix route need to be able to recognize the various greens that can be included, in order to weed out the less desirable ones (mostly romaine lettuce & spinach), but overall I think that spring mix can be a very useful thing for those of us who only own one beardie, don't have any local farmers' markets, & therefore waste the majority of any bundle of collard, mustard, turnip, dandelion, etc greens they might buy. Also, I can't imagine our Oolong is the only beardie who prefers the tender young greens included in spring mixes over the more mature greens sold in bundles intended for cooking.
JMHO, of course, & I've only been reading up on beardies since April. :}
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~Alice
1.0 Bearded Dragon (Oolong)
0.1 ferret (Lil' Guy)
7.4 cats (Angel, Goblin, Hush, Kirin, Sammy, Squee, Toes, Feets, Gypsy, Kana, Raisen)