It produces congested clumps of corrugated knobbly foliage with the distinctive Iron Cross marking. The leaves have a tough texture, but are rather brittle and tear easily. I find it less cold tolerant than the Rex Group, and if the leaf mass is seriously damaged, the plant takes a long time to recover.
Around 1980 I tried a series of hybrids between this and Rex Group Begonias, but didn't manage to get any viable seed to set.
As you can see, the leaves act like velcro on the falling Larch needles.