(1954)  
 
[This statement refers to Harrison's own R. rivalis, not the American species]
At this point the topic of the puzzling rose described by Smith as Rosa rubella was raised. This species (?) was erected in 1810 on the basis of Durham material, and its status has ever since been a problem to rhodologists. By comparisons made point by point with Smith's and other descriptions, and by a direct consideration of Winch's specimens, the speaker showed that in every respect R. rubella agreed with certain segregates in the F2 R. sherardi x spinosissima lots, as did his own R. rivalis described from Wheel Birks plants. He had, therefore, no hesitation in regarding R. rubella and R. rivalis as naturally occurring hybrids originating in a cross between R. sherardi and R. spinosissima. Obviously, since F2 plants so reared are fertile, the generation to which they belong remains undecided. Professor Heslop Harrison stated that in his opinion, based on certain experimental data, they actually belonged to the F2 lot.

(1954)  
 
At this point the topic of the puzzling rose described by Smith as Rosa rubella was raised. This species (?) was erected in 1810 on the basis of Durham material, and its status has ever since been a problem to rhodologists. By comparisons made point by point with Smith's and other descriptions, and by a direct consideration of Winch's specimens, the speaker showed that in every respect R. rubella agreed with certain segregates in the F2 R. sherardi x spinosissima lots, as did his own R. rivalis described from Wheel Birks plants. He had, therefore, no hesitation in regarding R. rubella and R. rivalis as naturally occurring hybrids originating in a cross between R. sherardi and R. spinosissima. Obviously, since F2 plants so reared are fertile, the generation to which they belong remains undecided. Professor Heslop Harrison stated that in his opinion, based on certain experimental data, they actually belonged to the F2 lot.