SOUTH AMERICAN PLANTS. 107 
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 Mierembergia 
has been already pointed out (p. 89). 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, estiva. 
* I can yet hardly venture to propose the separation of Lycium and 
Petunia from the Solanacee, although more than half persuaded of the 
propriety of doing so; but if in a more advanced stage of these inquiries, 
more forcible reasons present themselves, I hope not to incur the charge 
of inconsistency for this recommendation, and for having in the preceding 
contributions followed the views of all former botanists in regard to the 
classification of these two genera in the Natural System. It will be seen, 
however, from what has been here demonstrated, that Petunia is more 
closely allied to Salpiglossis than has been generally supposed; perhaps 
the Callibrachoa of Llarve and Lexarve (which I have not yet seen) will be 
found to be hardly distinct from Petunia. 
