If it weren't for the color, I'd say you got a "Feo" alata. "Florido" types are much easier to peel, being rounded, broad and cylindrical, not lobed (unless grown in heavy clay). I eat them all the same way, boiled, mashed and buttered. It looks like you got a tasty one!
The skin looks slightly tender, like it was picked young. The vine got its start late in the season, right? Not much time to grow. Did you save the little root?
Hi! Yes maby i harvest too soon... yes i saved them. That more round ones i don't know... they are good to eat? Do you have bulbs from this one? This is a new world opening... very excited! 
Nah, you harvested on time, the vine just had a short growing season this year.
The round ones are good. Kind of like your description, it's a neutral taste. Of all the yams, alatas are the softest, and can fall apart in the water if overcooked (thus the name "water yam"). The best ones will be fiber-free. Decent ones will be full of soft, tender fibers. The worst ones have distastefully-noticeable fibers (at least that's my opinion, the folks here enjoy most yams even if they have a preference). I haven't had a bad one in a long time, so I'm not sure if it's related to variety or other factors.
I have "Florido". They're the most common yam here in the markets, together with my favorite, the Guinea Yam (drier, starchier). We propagate them the same way, by planting the top piece after cutting it off of the rest of the tuber; they rarely produce bulbils, if at all. There's also plenty of feral alatas in the mountains. I have a bulbil-bearing one that has taken over the back hillside. I think it's yellowish inside, with purple-tinged skin. I haven't tasted it in a while, but I'm growing one in a tub, so I will soon.
There's loads of yam varieties. The local Ag. Research Station has many that I don't. I can't wait to pay them a visit. I hope to come back with a few esculentas and some of the rarer Guinea types.
Topic: Anyone grow Dioscorea alata (purple yam/ube)? (Read 12879 times)