It turns out the big begonia in my wall is Ricinifolia Immense, a rhizomatous variety.

I got a start for my ricinifolia Immense from a friend over 20 years ago.  I’ve propagated it, given friends starts, passed my plant on to someone else and just lately got a start back.  This plant LOVES being in the plant wall.  The growth is more lush than when it was potted.  The leaves are bigger, the stalks are longer.  The largest leaf on this new start is 17″ long and over 13″ wide.  The stem is a full 2 feet long.  This new start hasn’t bloomed yet.  I don’t expect to see a bloom stalk until this fall.

And I’ll be really glad when the weak chlorotic leaves age and fall off . . .