I made a surprising discovery at snow melt this year: the bark of one of the suckers (offsets) of my dogwood was not the same color as the original plant!
The plant in question, yellow twig dogwood (Cornus sericea ‘Bud’s Yellow’, which some authorities place in the look-alike species C. alba) is grown for its attractive yellow stems, especially visible in winter. The original species, though, has stems that turn red in the winter. ‘Bud’s Yellow’ originated as a yellow-stemmed mutation of the normally red-stemmed species (called, of course, red twig dogwood). However, my offset has gone back to the red coloration of its ancestor!
This kind of mutation (and yes, it is a mutation!) is called a reversion: the plant has returned to its original form. Reversions are actually quite common, most often seen in plants with variegated leaves or bi-colored flowers. Part of the plant starts producing “ordinary” leaves or flowers. This is the first time, however, that I’ve heard of a reversion in bark color.
Normally, you’re supposed to prune out reversions to preserve the attractive qualities of the cultivar. That’s because reversions are often more vigorous than the cultivar and tend to take over and crowd it out. But I think I’ll keep mine. It seems to me that as the yellow and red twigged plants mingle over time, the result will be quite attractive.
Nature: always full of surprises!