Rose with yellow sport
This bicolor rose in my neighbor’s garden has a shoot that is producing a single yellow rose. The majority of flowers on the plant are a combination of orange and yellow, so this particular shoot could simply be sporting back to its yellow rose parent. The plant could also be creating a “sport” that represents a genetic change in the plant material, in which case the shoot with the yellow rose could be propagated as a cutting to see if a new, all-yellow rose bush could be developed, different from the parent. Since this particular shoot isn’t growing from any of the main stems, it could also be a sucker from the rootstock onto which the rose is grafted. However, since most rootstocks produce either red or white flowers on suckers, my guess is that this shoot represents some sort of sport.
Gardening in the Mud 