THE BOTANY OF SOUTH AMERICA. 165 



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 Nicoiiana, 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 ofNico- 

 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 Fabiana. In 

 order to remove the doubts that may exist in regard to the 

 several species of this genus, I will offer a short enumeration 

 °f 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 

 ^described, that exist in the herbarium of Sir Win. Hooker ; 

 * propose to amend the generic character in accordance with 

 these observations, in the following manner. 

 ^ierembergia,R. etP. — Calyx tubulosus, 10-costatus, semi 

 S-fidus, laciniis linearibus, subinsequalibus, acuminatis. Co- 

 rolla hypogyna, tubulosa, tubo gracili, elongato, rarius sub- 

 mfundibuliformi, ore campanulato, limbo amplo, expanso, 

 hreviter 5-lobo, lobis rotundatis, aestivatione plicato. Sta- 

 m ina 5, corollse fauci, rarius medio inserta, exserta, raris- 



