Sounds like what they call a "sport". Apparently a number of new cultivars have arisen from "sport" branches (where some sort of mutation may have occurred), and these were vegetatively propagated en masse, if the trait continued with cuttings from that odd branch.

thanks Jenny
It appears you are exactly correct.
Previous to checking out your response I had the misunderstanding that "sport" was reserved for whole plants that were products of sexual plant reproduction. Now I will be trying to figure out what caused these asexual sport branches on established plants???????????
Dave

Chimeras are common it the plant world. They occur when a cell undergoes some sort of mutation. The mutation may be spontaneous or it may be induced by an extraneous source, like irradiation or treatment with chemical mutagens. If the mutant cell is is found near what's called the crest of the apical dome, then all other cells which occur through division of that cell will be duplicates of the mutated cell. When this phenomenom occurs, there will be cells of 2 different genotypes growing side by side in a plant tissue, a chimera.

If the mutation occurs in a plant area where the liklihood of extensive further cell division is unlikely, then the probability of detecting or noticing the mutation by cursory inspection of the plant as a whole is low.

Al

Awesome information Al!
Thanks!
My favorite forums are mostly Roses, Seeds and Bonsai but thought I would give this one a try with this question. Appreciate your response. Exciting to learn.
Dave

I'm hoping to learn much here as well. See you around.

Al

So this reminds me of a spirea I just trimmed for a second bloom. It had some yellow striped leaves at the base. Was this spirea once all yellow varigated? I know that with yellow varigated euyonomus (great spelling) if you get a pure green leafed branch you cut it out. Same deal here?

Yes, cut it out if you wish to retain the uniform variegated appearance. There are many kinds of variegation, & in part they depend on the tissues that have been affected. Remember that variegation (except pathological) depends on two genetically different tissues living side by side. Variegation can vary between nearly completely stable to very unstable. It's not unusual for variegated tissues in a plant to die out & the plant to revert to an all green form.

Al

Al, thanks for the very cool, detailed info!

So, the sport is the mutation, so is the chimera the entire plant with the mutation?

I have a Phlox 'Bright Eyes' which I have had for 3-4 yrs. this year, one stalk is a medium salmon color, and the rest of the phlox is the pale pink with the deep pink eye. I figured the salmon stem was a sport, but chimera is a new word for me.

Toni

Technically speaking, a sport is a plant or plant part come into being as result of some mutation, chimeral rearrangement, or recombination that is usually genotypically different from the original plant. A chimera is a plant with two or more genetically different cells growing side by side.

I think what you're asking can be answered by saying that chimeras are best described as sports (usually naturally occurring chimeral rearrangements) that have been vegetatively reproduced.

Forgive me if I don't have some detail exactly right. Most of my knowledge in this area is incidental to what I have learned of witches brooms & other mutations as they apply to plants commonly used in bonsai culture.

Al