That looks to be an 'Easter Cactus.' That being said, they're known to randomly throw pieces of themselves off (not sure that I ever found the reason for that). The "black" edges are actually dark purple; it's responding to the bright light from your South window. The more sun holiday cacti receive, some of them start to blush (I call it blushing). I had a 'Thanksgiving Cactus' that looked like that at purchase and it never lost it's purple edges. Even right now at my MIL's dark livingroom, it's still purple edged and growing. Nothing to worry about though, so enjoy it. :)

Planto

This post was edited by plantomaniac08 on Thu, Aug 7, 14 at 8:37

Can I water little more frequently these days? I submerged the pot when soil was dry and leaves were limp and after left it alone for about 3 weeks. Haven't got the hang of watering succulents yet o.O

Ideally you shouldn't let it get limp...but better that than overwatering.

Despite the word "cactus" in the name, 'Easter Cactus' don't want the same care as that of a "desert" cactus. They are "tropical" cacti and would appreciate more water than that of their counterparts.

It's difficult to say how often you should water, as I don't know how often it dries out. I can see you have it in a plastic pot, but I don't know what potting mix you have it in. I'd say you're safe to water it once you can dig your finger in the pot a little bit and it feels dry, but I can't tell how deep your pot is or how wide. Different factors affect how fast a plant dries out, from the potting mix used, to the type of pot (plastic or clay), to the amount of sunlight. Ideally, you don't want it to dry out completely between watering, just slightly. Their care in the Winter is going to be different than Spring/Summer though. You don't want to water as frequently in the Winter.

'Easter Cactus' are finicky, so too much or to little of something can cause them to throw a leaf or a branch. I think they've been responded to as Divas lol. Yours looks rather happy though. I think once you get the watering figured out, it'll explode on you. ;)

Planto