If we held a contest for the funniest looking sprouts, I think the moonflower would win.
Reminiscent of of a morel mushroom when it first emerges, the seedling will rapidly turn green and unfold gigantic leaves that quiver and grow even as you watch. Never wanting to miss the show, I always start mine indoors, at eye-level.
Moonflower vines root easily in water. All parts are poisonous. The heavenly scented flowers open in the afternoon, shortly after morning glories have closed up, so they make wonderful companion plants for one another. Since moonflower (Ipomoea alba) is a different species it will not cross-pollinate with the other morning glories. That makes it ok to plant them together in order to have red or blue flowers and white ones in the same area.
I blogged about moonflowers here:
Feb 23, 2010: More Moonflowers
Sep 27, 2009: No Bees in my Home Please