42 



pinnate, as described by M. Dunal in Solanum Commerso7iii ; but, as the plant advanced to flower, they lost 

 this character, and became unecpially pinnate as in the cultivated potatoe. This plant, I have no doubt, is 

 identical with the S. CowimerwmV of Dunal, and confirms the opinion which I formerly advanced, that 6\ Com- 

 mersonii is the Sola/mm tuberosum in a wild state. After a careful comparison of this plant with different 



vai-ieties of So/a«MW /wieros^m, I have not been able to discover a single character by which they could be 

 separated as distinct species, and the differences observable between them are of little botanical importance in 

 this tribe of vegetables, and are merely what would be expected to exist between the wild and cultivated state 

 of the same species. I have been induced to say thus much on this subject, having formerly ventured an 

 opinion respecting these two plants being of the same speeds."— Joumal of Science and I he Aris, Nos. 10& 28. 



In the foregoing I have, I trust, satisfactorily proved the existence of the potatoe in a wild state on both 

 sides of the South American continent. In further confirmation of tlje propriety of this opinion, whicii, 

 indeed, seems now to he generally admitted, 1 may mention that Mr. Dickson of Liverpool, a gentleman of 

 great intelligence, and an acute observer, who has recently returned from Buenos Ayres, where he has resided 

 many years, assured me that the wild potatoe, which he knew well, grows in the greatest abundance in the 

 vicinity of that city j and that in foliage and habit it resembled so much the cultivated sort, that no difference 

 was to be observed between them, unless that the roots of the former were small and not eatable. He stated 

 also, that it was always regarded as a weed, and rooted out from the gardens and cultivated grounds 

 accordingly. The wild potatoe is evidently susceptible of great improvement ; for, having obtained, from tlie 

 Horticultural Society, some cuttings of the plants brought by Mr. Caldcleugh, the tubers have now increased 

 in size and improved in quahty. _ 



F 



i 



m 



Mr. Sabine, the indefatigable Secretary of the Horticultural Society, has lately given, in the " ^d part of 

 the 5th volume of the Transactions of the Horticultural Society," a paper on the potatoe, in which he endea- 

 vours to prove that the Solanum Commersonii of Dunal is distinct from Solamtm tuberosum. He has accom- 

 panied his account with a figure of Commerson's original specimen, from which Dunal formed his description. 

 Not having seen the specimen itself, I shall endeavour, from the figure, to reconcile the differences apparently 

 existing between these two plants. The figure clearly indicates, that the specimen has been the production 

 of a weak and stunted plant. This is shown by the imperfect development of Its leaves, which exactly resem- 

 ble those of a seedling potatoe. Dunal and Mr. Sabiue appear to lay great stress on the greater size of the 

 terminating leaflet ^ but this inequality of the terminal leaflet is common to all plants with folia impari-fmnaia, 

 and more especially to the species of Solanum with pinnated leaves. After seeing the figure, I went and 

 examined a field of potatoes, and was fortunate in picking up several slender stems, agreeing in' this point so 

 exactly, and in having the lower leaves almost simple, that on shewing them to the distinguished President of 

 the Linn^ean Society, Sir James Edward Smith, he said there could not be the smallest doubt as to their iden- 

 tity in these respects. Tlie corolla of Solanum Commersonii is described by Dunal as quinquefid, and so it is 

 represented in the figure; but it Is not at all probable, that two plants, agreeing in other respects, should yet ' 

 differ in this important point. The joint of the pedicels mentioned by Dunal, and also occurring in Solanum 

 tuberosum, is not noticed in the figure. I mention this circumstance merely to shew how little confidence is 

 to be placed in figures taken from dried specimens: for, were the form of the corolla and the disposition of the 

 lacmlte to be relied on, they would remove this plant not only from the ^eims Solanum, but also from the 

 order to which it evidently belongs. 



I 



I have lately received from my friend Mr. Cowan, now residing at Lima, and to whom I have been so 

 often obliged on former occasions, a root of the celebrated golden potatoe, Patatas amirlllos of the Spaniards 

 which grows wild about 16 leagues from Lima. This, which is now growing with me, proves to be nothin ' 

 more than a variety of Solanum tuberosum. 





