A sport is a mutation. Rose plants mutate color sports, climbing sports and dwarf sports.
[From The Practical Book of Outdoor Rose Growing
, by George C. Thomas, Jr., p. 25:] Sports are purely a matter of chance, and occur when any given variety shows a bloom or habit of growth different from the accepted plant. [The author cites two well known examples of sports, p. 26:
] 'Duchess of Albany'
(a sport of 'La France'
) and 'Ecarlate'
(a sport of 'Camoens'
). With these two new varieties the habit of growth of the plants remained practically the same as their parent plants; it was only in the color of the rose that the change manifested itself.
[From The Old Rose Informant, by Brent C. Dickerson, p. 70:] the Centifolias... often tend to turn back into the variety which sported them