pale glaucous-green, obscurely costate, downy, all of them 

 alternate and scattered, except the lowermost, which ap- 

 pear almost whorled, the uppermost ones on the young 

 branches subsetaceous. Flowers terminal on the young 

 branches. Calyx with its tube attenuated at the base, 

 white and membranaceous, with ten green, prominent ribs, 

 scarcely downy ; limb of five linear, spreading, green and 

 somewhat foliaceous, slightly downy segments. Corolla: 

 tube much exserted, very long and exceedingly slender; the 

 limb spreading, convex, unequally five-lobed, white, streak- 

 ed with purple, having a yellow eye where it is inserted 

 on the tube : the lobes rounded, obtuse. Stamens five. 

 Filaments rather short, inserted in the mouth of the tube, 

 scarcely connate, two in front of the style and three behind 

 it, somewhat equal, two longer than the rest, and one 

 (the centre of those behind the style,) smaller, curved at 

 the apices. Anthers roundish, reniform, two-lobed, two- 

 celled, the cells opening laterally by a vertical fissure. 

 Style as long as the stamens. Stigma transverse, anterior, 

 oblong, acuminate at each extremity and recurved, green, 

 viscid. Germen ovate, dotted, two-celled, cells with many 

 ovules attached to the receptacles of the dissepiment. 



The Genus Nierembergia, characterized by the ex- 

 tremely slender tube of its corolla, inhabits exclusively the 

 New World, and appears to have an extensive range there; 

 one species of those hitherto described being a native of 

 Peru (N. repens, R. and P.) another of Mexico, (N. angus- 

 tifolia, H. and K.) and a third of Monte Video, (N. pubes- 

 cens, Spreng.). To these, I have the pleasure of adding a 

 fourth, a native, like the last, of the vicinity of the Uraguay, 

 but in botanical character nearly approaching the Mexican 

 plant. Prom that it differs in the pubescent stems and 

 leaves, as well as in the structure of the stamens and stigma; 

 so much so, that I should almost be inclined to consider 

 them generically distinct ; only that the figure and descrip- 

 tion of N. angustifolia being made from dried specimens, 

 the learned authors might be deceived in the appearance of 

 such minute parts, and thus the difference may be account- 

 ed for. 



Our plants were raised from seeds sent from Buenos 

 Ay res, by Mr. Tweedie, and promise to bear the open air 

 in summer. They flowered in July, 1831. 



Fig. 1. Leaves. 2. Calyx. 3. Front view of Stamens and Style. 4. 

 Back view of ditto. 5. Anther. 6, 7. Front and back view of the Stigma- 

 8. Germen. 9. Section of ditto.— Magnified. 



