What kind of plant will my Red Cherry Plum stems grow into?

Question

I bought this small mini red cherry plum seedling on ebay last two weeks ago, I want to know what these two plant stems will look like when they are mature... And describe what will they look like when they get very big. Because I wonder what will these two plants look like when they get big?

• The left one's stem is some kind of softer and much greener than the right
• The right one's stem is much harder-branched but smaller than the left
• They are seperates, their roots are different (not together)
• The left plant don't have a bunch of thin hair-spreading-like roots coming out from the single stem underneath but its roots are looking like it's sliding right following some long thin-like rounded knuckle which has a dark-brown spot at its bottom end that are not sending thin hairy roots from beneath it, or maybe it will in the future?
• The right plant does have hair-spreading-like roots coming from its single stem underneath

I bought 1 small plant but there are 2 different plant stems bundled in a pink elastic band.

Answer 1

From your question, and the answers in comments, it seems it's not clear how many plants were supplied, but it seems to be three. Whether they're all the same or not is hard to say at this stage, but you should assume they are. One of them seems to be a non starter, and as you're keeping them in a pot, I'd be inclined to remove the one that's not doing anything and dispose of it, and pot the other two separately. If they genuinely are 'mini' cherry plums, then they're probably like the one shown on the right in the image here http://www.vanmeuwen.com/fruit-and-vegetables/fruit-trees/stone-fruit-trees/mini-fruit-trees-cherry-plum/69141VM

You should also use much smaller pots than the one shown in your picture, and pot them up into larger pots as and when necessary over time, otherwise the roots they form will wander and won't form a firm rootball, and there's a risk that all that unoccupied potting soil will 'sour' and the plants won't grow properly. Probably 6-9 inch pots will do initially, going up a size or two each time you pot on. Remove them carefully from the pot they're in currently, and do it as soon as possible, before any roots they've formed get very long and widely spread, and try not to break any; use new potting soil to place around the existing roots, and water in.

I can't tell whether these plants are indoors or outdoors - they need to be outside, but if they're indoors currently because it's too cold, when you do want to put them out, you'll need to harden them off first.