PHYLLOCACTUS X CEREUS. 95 



HYBRIDS OF PHYLLOCACTUS CRENATUS AND CEREUS 

 GRANDI FLORUS . 



[Phyllocaclus X Cooperi, P. X Wrayi, and P. x Thomasianus .] 



By A. Worsley, F.R.H.S. 



In tracing the parentage of these alleged hybrids we meet with 

 contradictory assertions and evidence. 



(1) As to the parentage of Phyllocactus x Cooperi. I pointed out 

 in 1906, at the Third International Conference on Genetics held in 

 London,* that this plant could not be classed as an " ascertained 

 hybrid." To avoid any possible error in nomenclature I interviewed 

 Mr. Cooper, after whom P. x Cooperi received its name, and he kindly 

 visited my garden and examined my plants of Cooperi whilst they were 

 in bloom. He was quite positive of the identity of my plants with the 

 original Cooperi, and pointed out certain peculiarities of this form 

 (such as its habit of carrying flowers at the bases of the stems only 

 just above the ground). He then gave me the following information 

 about its earliest history. He obtained it about 1870-75 from the 

 collection of Mr. Wilson Saunders of Reigate ; its origin was then 

 unknown and there was no claim then made that the plant was a 

 hybrid. Some time in 1890-98 this plant was in the Kew collection 

 as a hybrid between P. crenatus and C. grandiflorus. I flowered and 

 described it in 1899. It is now widely spread in gardens. It is said 

 that P. crenatus and C. grandiflorus have been recently re-crossed 

 on the Continent and have again given Cooperi, or something very 

 like it. On the other hand Prof. Gurke says that this hybrid was 

 raised in Germany about 1880 by the father of the present F. A. 

 Haage, Junr., and resulted, not in Cooperi, but in Wrayi] — a plant 

 quite distinct therefrom. 



I have raised more than 1000 seedlings of Cooperi and have not 

 found a single one of them that reverted to the reputed male parent. 

 But all these plants were crosses, and I think it is very difficult to 

 impregnate Cooperi with its own pollen. All my chance fruits proved 

 to be crosses. 



(2) Even as to the comparatively modern P. x Wrayi some 

 confusion has arisen through faulty systems of genealogy. Instead of 

 following the well-established rule of tracing ancestry by mother-kin, 

 confused statements are put forward and the reputed male parent 

 is sometimes given priority to the known female. For instance, 

 in Bliihende Kakteen the parentage of this plant is given in the heading 

 as C. grandiflorus x P. crenatus, but a little further down the order 



* Report Conference on Genetics, 1906, R.H.S., pp. 407-9. 



f Blukcnde Kakteen [Profs. Schumann and Gurke], Pt, 16, PI. 62 (coloured). 



* 



