NOTE ON "SOLAXUM ETUBEKOSUM." 



57 



is not known, but it is thought to have been introduced from a wild 

 source. Some years ago we had tubers from Edinburgh, through the 

 courtesy of Mr. Lindsay, F.R.H.S. ; and, as in many other gardens, we 

 found the plant to be quite hardy, but, as Mr. Sutton observes, to produce 

 tubers abundantly (and under garden cultivation much larger than 

 walnuts) and to have a hispid calyx : characters — which are well shown 

 in the excellent plate * which adorns Mr. Sutton's paper. 



Thus, in the two characters upon which Dr. Lindley relied to separate 

 his species from S. tuberosum the present plant is like S. tuberosum. 

 It would therefore appear that this plant is not specifically identical with 

 the one Dr. Lindley described, though with which, if with either, of the 

 described species it should be included appears doubtful. Lindley 's plant 

 is probably lost to cultivation, but the type specimen is in the Lindley 

 herbarium at Cambridge. 



Mr. W. G. Baker f considers Lindley's plant " likely to be a variety 

 of tuberosum" and notes there is a wild specimen, labelled with the same 

 name in Mr. Eeed's Chilian herbarium, which differs from the " type by its 

 more hairy leaves and calyx and more pointed calyx teeth." 



The Edinburgh plant, except in the characters mentioned above, agrees 

 well with the description of Dr. Lindley's plant and in addition differs 

 from S. tuberosum by the fruit, which is globose, having small whitish 

 warts upon its surface. [Whether this is always the case is doubtful, 

 since Mr. Sutton t figures a smaller berry without warts.] In addition 

 Mr. Sutton observes that the pollen of S. etuberosum is always elliptical 

 (a character which Mr. Paton does not confirm), and as this character is 

 common to the undoubtedly wild forms of tuberous Solanums he con- 

 cludes that in this plant we have to deal with a true wild species. The 

 varieties of the cultivated potato produce pollen which varies in shape. 



Perhaps the greatest interest attaching to the plant lies in the fact 

 that both Mr. Sutton and Mr. Paton have found it, though growing 

 among cultivated potatos attacked by the dreaded Phytophthora infestans, 

 to remain persistently free from the disease induced by that fungus ; an 

 observation that we are able to confirm. Since Professor Biffen has 

 shown that, at least in wheat, disease resistance may be an hereditary 

 character, it is to be hoped that by using this form as one of the parents 

 (or grandparents) we may obtain a potato at last which will resist the 

 attacks of the fungus which causes more loss every year to potato growers 

 than any other. 



* I.e. t. 46. f " Tuber-bearing Solanums," Journ. Linn. Soc. 1884, p. 489. 



% I.e. pi. 46. 



