We have a gal here that is excellent on the cactus tribe.
show her the pictures, and I bet she will get them down pat. Opuntia 'Jacob's Coat' I had as a kid and not it will not belong with the others. Wait until they flower and you will see the differences as well, as they grow there also may be big differences, good luck enjoy this forum, and don't let them get you. Norma

The O. cochenellifera varigata is different from both the o monocantha varigata.and the Maverick opuntia. The maverick looks like is stays small with dimmunitive pads. The cochinellifera will get sizable. i have seen it 6 feet tall and I hear it gets larger when in a friendly place.. It's structure is more like a hand , where as the O . monocantha starts out more vertically. The monocantha has many smaller pads that forms on the central pad that keeps growing upwards, but the central pad remains dominant structure off the plant. The O. cochenillifera wanders all over the place from it's many fingers on its hand. The O monocantha also have a tinge of red on the tips edges. the Cochinellifera does not and the color greens are more analagous , w. The cochinellifera and the o. monacantha are hardy to Zone 9a... There are a lot of differewnces between the two. The maverick is a cultivar of Opuntia Monacantha variegata. I am not familiar with it so I can't say if it is just a cultivar Name, or a genetically tweeked version of it. It looks smaller than the normal Joseph's coat.
http://davesgarden.com/guides/pf/go/139679/
http://davesgarden.com/guides/pf/go/60006/

sorry I can't be of more help with the other two.- mara

Besides being bigger and a different species, the O. cochenillifera in the picture does not look monstrose (as the other two do).

Thanks for the replies. I read up a little on them.

And, it looks like the cochenellifera does get really big really fast. It does appear to be free of spines. Pretty plant but probably not good for pots.

The seller of plant #4 said that his doesnt have spines and he would upload a picture.

Maybe someone that has kept the maverick or monocantha variegata will add some information.

does all monocantha have spines?

It's "monacantha" (mon(o) (one) + acantha (spine or prickly), can't check right now but I think the "o" has disappeared because it appeared in front of another vowel)). Can make it easier when searching.

The "standard" monacantha has spines, but Opuntia species are variable and it is often possible to find forms with higher or lower number of spines, so finding a spineless monacantha is not impossible at all.

I had a monstrose Opuntia a long time ago, and it grew fast. Too fast.

I have spent a couple of hours looking at pictures and following leads on variegated opuntia. It appears just as you said tjicken. the amount of spine varies from 'scary' to 'where is the spine' There is even one that I found Opuntia vulgaris aureovariegatus that I swear is the same plant as the COCHENILLIFERA. So I am no further along than earlier today. Looking for heavily variegated, as few spines as possible, will stay in a one gallon or so pot for at least two or three years. and montrose would be nice. So it looks like the maverick, but with as few spines as possible might be the right one.

O. vulgaris has been lumped under monacantha, i.e. it is either a minor variation or just a synonym.

I had never seen the word aureovariegata (as the feminine form is spelled) before, it seems to express that the chlorophyll-free parts are yellow. Could even be a plant bought as 'Maverick', but the owner decided to use a less specific, home-made name. It is often very difficult to understand why a particular name is used, if it is real, made up or if the owner remembers wrong.

If a plant has a name within single quotation marks like 'Maverick' I expect it to be a clone, i.e. all plants should have the same DNA. but I suspect that the same plant goes under several names and one name is applied to different clones (I have seen both green and variegated 'Maverick'). Places like ebay are especially untrustworthy (I guess you understood that before you started this thread).

Unless you can find a trustworthy supplier or an expert on variegated Opuntia shows up I'm afraid you'll have to trust your instinct.

I am growing both the varigated chochenillifera and and needless O.monacantha in pots (smaller than 1 gallon) for about a year now. My experience is that the variegated Cochenillifera is much slower grower that the all green O cochenillifera. It really does bolt out of the gate. Maybe there is more than one variety of it too. I saw some pads of it at the Austin C$S show and was amazed hoe large they were compared to mine. maybe I am doing something wrong..

wanton, are your forms normal or monstrose? do they make pads or are they just kind of stalled?

Well, I am not quite sure what "monstrose" means. I see it in names and understand it to be about the structure, but I am a semi ignorant newbie to cactuses. Most of what I have collected are large opuntias from the southwest. I grow them outdoors. Not many south american ones. I am going to take a stab at it and say that the cichinellifera is a not monstrose and the Joseph's coat is.

A normal cactus grows from the top, while a monstrose one grows from almost all areoles, resulting in a deformed plant, like this:
http://home-and-garden.webshots.com/photo/2271934420097446201qzKiAt

Monstrose Opuntia do not attain that weird shape, instead they branch heavily, both 'Maverick' and 'Joseph's coat' are monstrose.

Yesterday, I found a 4 inch pot of variegated monstrose opuntia in a local nursery. I got it to see how it grows. This nursery doesn't label any of their plants. Now, the question is, how do I tell the difference between Maverick and Josephs Coat? Any ideas?

The plant I bought is exactly like the one on the page below. It has all the same little growths out of all the Areoles (correct word?) They have this one listed as maverick.

Here is a link that might be useful: picture on daves garden