What kind of Dendrobium?

[Selmo]

Got these as a throw away last November, with no ID. I know that they are dendrobiums, but what kind? The first one has big fat nodes at the top of the cane and thin nodes at the bottom of the cane. Has not bloomed yet, the second one has thin canes all the way up the plant. It has bloomed last January. It only had one bloom but looks as if it should have had several blooms on the spike. Would like to know if they need a winter rest or when they may bloom. Any help is appreciated