CONTRIBUTIONS FROM THE WISLEY LABORATORY. 83 



CONTRIBUTIONS FROM THE WISLEY LABORATORY. 



XXII. — The Rogue Wallflower. 



By F. J. Chittenden, F.L.S. 



From time to time there appears among wallflowers a rogue form 

 apparently without petals and looking at a cursory glance as though 

 the flowers had failed to open. This rogue form is not confined to 

 any one variety, but occurs in both yellows and reds. 



The form has been known for a long time and has even received 

 a botanical name, for A. P. de Candolle * describes it under the 

 name Cheiranthus Cheiri y gynanthems, with the following diagnosis : 

 " Antheris nempe in carpella mutatis." It appears to arise suddenly 

 from time to time, but, as the observations to be described below show, 

 it may possibly be that certain apparently nornial individuals among 

 wallflowers are so constituted that their seed necessarily produces 

 both normal and rogue form. That is, they may be hybrids in the 

 Mendelian sense and, so to speak, carry the characters of both normal 

 and rogue forms. On the other hand, we have no evidence to show 

 that the rogues do not arise suddenly as seminal sports. 



The malformation existing in the rogues is a very peculiar one, 

 in which both petals and stamens are involved. The petals are 

 reduced to oblong coloured pieces about the length of the sepals or 

 a little shorter. A remark in Masters' " Vegetable Teratology " f 

 seems to infer that at times the petals may be developed normally. 

 He says, " In most of the flowers of this variety the petals are smaller 

 and less perfectly developed than usual." Brongniart J makes a 

 similar remark : " Dans ces Cheiranthus monstrueux, qui etaient tres 

 nombreux dans les parterres du Museum en 1841, les sepales et les 

 petales existent dans leur position habituelle, mais en general les 

 petales ne prennent qu'un developpement imparfait, ce qui signale 

 immediatement les plantes qui sont le siege de cette monstruosite." 

 We have not, however, met with any cases in which normal petals 

 were developed. It is almost to be expected that such cases would 

 occur, for it is scarcely credible that a single character-determinant 

 should produce the remarkable and dissimilar abnormalities which 

 occur in both petals and stamens. 



* DC. Prodromus, I. p. 135 (1824). 



t Masters, M. T., Vegetable Teratology, p. 305 (1869). 



X Brongniart, A., " Sur quelques cas de transformation des dtamines 

 en carpelles." Bull, de la Soc. Botanique de France, t. 8, p. 453 (1861). 



G 2 



