SOUTH AMERICAN PLANTS. 89 
NIEREMBERGIA. 
I have already offered some reasons (p. 71) for showing why 
this genus, hitherto considered as belonging to Nicotianee, 
should be separated from that sub-tribe. Several species are 
now cultivated in England, so that it is not requisite to enter 
into any particular details, but it is essential to define the 
exact limits of this genus, especially as much resemblance 
exists between several of its species and some kinds of Petu- 
nia and Nicotiana, which often renders it difficult, from mere 
external form, to determine to which of these three genera 
they should be referred. It is, however, distinguished by 
having the divisions of the calyx usually acute and rigid, 
not foliaceous ; the tube of the corolla is usually very elon- 
gated, and more slender than in the Petunoid section of Nico- — 
tiana, though it sometimes approaches in form to some of 
the smaller flowering Petunias; the stamens are generally 
inserted in the mouth of the corolla, rarely in the middle of 
the tube; but its most prominent characteristic, is that of the 
peculiar form of the stigma, which is in the shape of an in- 
verted crescent, with its horns curved round in front, embrac- 
ing the anthers within its grasp; the capsule also differs from 
that of the two genera above-mentioned, by having its valves 
scarcely, if at all, introflexed. I have already pointed out the 
difference in its stipitate ovarium, and in the form of its 
pollen grains, in which respects, and in its distinctly bilamel- 
lar stigma, it affords a close approximation to Fadiana, In 
order to remove the doubts that may exist in regard to the 
several species of this genus, I will offer a short enumeration 
of each, with the more striking characters, as far as I have 
been able to observe them, and will add some new species 
that I met with in 1825, together with a few others, yet 
undescribed. that exist in the herbarium of Sir Wm. Hooker ; 
I propose to amend the generic character in accordance with 
these observations, in the following manner. 
Nrerembercia, R. et P.— Calyx tubulosus, 10-costatus, semi 
5-fidus, laciniis linearibus, subineequalibus, acuminatis. Co- 
N 
