THE BOTANY OF SOUTH AMERICA. 183 



the capsule is generally of more membranaceous texture, 

 notched and entire at the apex, it is sometimes more coria- 

 ceous, when by the least pressure, the valves often split as in 

 Nicotiana : there is hardly, however, so great an introflexion 

 in the lower portion of the valves. The corolla of Petunia is 

 often somewhat oblique, and marked with several branching 

 and reticulate veins on one side, as in Salpiglossis, corres- 

 ponding with the shorter pair of stamens. 



In Nicotiana the inflorescence is always in terminal panicles, 

 while in Petunia, the flowers are invariably axillary and soli- 

 tary, on a peduncle which is generally deflexed in fruit : the 

 ovarium as in Nicotiana, is always supported upon a 2-lobed, 

 not a 4-lobed disc, which conceals the short columnar sup- 

 port: the lobes of the disc correspond with the sutures. The 

 approach to Salpiglossis* is shown in the didynamous charac- 

 ter of its 4 longer stamens, which are inflected towards each 

 other in 2 unequal pairs, while the fifth always shorter, though 

 generally fertile, is sometimes sterile, and is placed between 

 the longer pair. The style is likewise declinate at its apex, 

 and the stigma though it bears much analogy in its structure 

 to that of Nicotiana, is doubled into a somewhat bilabiate 

 form. The difference between this genus and Nierembergia 

 has been already pointed out (p. 165). The following is 

 offered as an emended generic character. 

 Petunia : Juss. — Calyx tubulosus, 10-nervis, 5-partitus, 

 laciniis spathulatis subfoliaceis. Corolla hypogyna, infun- 

 dibuliformis, vel subhypocrateriformis, tubo cylindraceo 

 vel ventricoso, limbo patenti ineequaliter 5-lobo, sestiva- 



I can yet hardly venture to propose the separation of Lycium and 



ettinia from the Solanacea, although more than half persuaded of the 

 Propriety of doing so ; but if in a more advanced stage of these inquiries, 

 ^we forcible reasons present themselves, I hope not to incur the charge 

 of '^consistency for this recommendation, and for having in the preceding 

 ^ntributions followed the views of all former botanists in regard to the 

 ^assification of these two genera in the Natural System. It will be seen, 



owever, from what has been here demonstrated, that Petunia is more 

 cosely allied to Salpiglossis than has been generally supposed ; perhaps 



e Callibrachoa of Llarve and Lexarve (which I have not yet seen) will be 



Qnd to °e hardly distinct from Petunia. 



