Itching for an alternative to punch up that shade garden of impatiens? Begonias are a wildly varied bunch, top to bottom. The foliage may mimic pointy stars, tapered angel wings, round beefsteaks or ...

We think we know begonias: those round waxen blobs with white or pink icing sold in six-packs; the speckled thing your grandmother grew or the gaudy plumed ornaments that thrive along the coast. But ...