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III. Observatiom on the Tropseolum pentaphyllum of Lamarck. By Mr. David 



Don, Lihr. L.S. 



Read December 18th, 1832. 



This curious plant is a native of the regions bordering on the Rio de la 

 Plata, where it appears to be far from rare, as it occurs in most of the collec- 

 tions that we have seen from those countries. It was first discovered by 

 Commerson ; and from the materials collected by that indefatigable natu- 

 ralist, Lamarck was enabled to give a figure and description of the species in 

 the botanical part of the Encyclopddie MModlque, under the appellation of 

 Tropceohan pentaphyllum—^ name, it will be admitted, misapplied to a plant 

 whose leaf is merely deeply lobed. Another figure and description of the same 

 plant, but under a different, although no less objectionable name, occurs in 

 an academical dissertation on this genus, by Professor Hellenius, and published 

 at Abo in 1789, a short time after those by Lamarck had appeared. M. Au- 

 guste de Saint-Hilaire has likewise given a figure and description of it in his 

 Plantes Umelles des BrasiUens. Notwithstanding these several authorities, 

 the characters of the plant have been hitherto but partially understood ; and 

 it was not until its recent introduction to the British gardens that the pecu- 

 liarities of its structure have been ascertained. In the month of August last, 

 while on a visit at Edinburgh to my much-esteemed friend Mr. Neill, to whom 

 we are indebted for its introduction, I had the pleasure of seeing this interest- 

 ing plant in flower, and subsequently with ripe fruit, which has enabled me to 

 determine its claims to be regarded as the type of a new genus. The most 

 remarkable peculiarity is in the nature of its fruit, which is a black, juicy 

 berry, not unlike, both in appearance and flavour, the Zante grape. Besides 

 the reduced number of its petals, a character the importance of which I am 

 not disposed to insist much upon, the genus likewise differs in the valvate 

 aestivation of its calyx, (a distinction first pointed out by M. Auguste de Saint- 

 Hilaire,) that of Tropceolum being imbricate. Neither of these characters has 



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