The first is Aloe vera v. chinensis. (blooms orange) The 2nd (although that looks like more spots than usual) which is much larger, thicker leaves & yellow blooms, is Aloe vera/barbadensis. I believe it has been reclassified with the latter name, but most people are still calling it by the former (vera), so one or the other is listed as a synonym. See link below for a pic of an Aloe vera/barbadensis ~Rosemarie, who hangs out on the C&S forum, but pops over here on occasion =) Here is a link that might be useful:

There seems to be some confusion again with common names - Aloe vera is Aloe vera :-) Although that term is sometimes used to refer to ANY kind of aloe, there are not two species of true or common, aka medicinal aloe. There ARE many species of aloe....as many as 400 have been registered but true aloe, Aloe vera (formerly Aloe barbadensis), is the one noted for medicinal purposes. There is some documentation that Aloe arborescens also has similar medicinal properties but as the species name suggests, this has a much more tree-like growth habit and develops a distinct stem or trunk. The difference in growth habits between the two plants shown in the pics is simply due to age and maturity. Aloe vera will form a full rosette if given sufficient time and proper growing conditions. Check the Wiki photo linked below. The smaller ones that appear to only grow laterally rather than in a round rosette of leaves are just young, immature plants (offsets or pups) and hampered from full development by lack of time and indoor growing conditions. Here is a link that might be useful:

There are three "major" medicinal Aloes: Aloe arborescens (seriously people, if you live in SoCal, use this!), Aloe saporina, and Aloe vera. These are the standard, "put it on what hurts" Aloes, good for burns, scrapes, and other topical ailments. There are many other species used for other reasons (purgatives and laxatives are common!). In reality, most stuff sold at supermarkets is just the inner gel of the leaf with some other stuff mixed in. The thing is, most of the "medicinal" compounds are in the yellowish sap than runs more in the skin of the Aloe than in the middle, clear gel. If you've ever used real leaves instead of a supermarket bottle, you'd have found that it is much more effective, but leaves a yellowish, sticky residue that would be too uncivilized for something sold in the beauty department. So would A. maculata work? Probably, since the inner leaf gel is mostly just water in all species, and the supermarket bottles are mostly just water too. Then again, it is possible that it has some sort of compound in it that might actually irritate your skin. Depending on how much of a gambler you are (and how much extra A. maculata you have laying around) it may be worth a shot. Then again, I'm not even remotely a doctor, so maybe I'm not the best person to be listening to!

It looks like a very "messy" example of one type I grew in most places I lived. I was told that it's good for internal pain (among other things), eg bones, mucles... I tried it and it seemed to work on me. So I used it while the kids were still home. Each time we moved I'd find another same Aloe in the area. So I'd break of a branch, from the back if I could, just stuck it in the ground and it always grew. I'm not sure about the "aloin" though, maybe we were just lucky. Better check it before using. For years I've been looking for an online scource for the medicinal uses for the different species of aloe. Those that have those uses anyway. If anyone knows of any I would love for someone to provide a link or a name. Our whole family suffer from sensitive skin ailments. Thanks