_Nierembergia_ is a genus of ornamental greenhouse plants, easily distinguished from the Petunias by the great length of the tube of the corolla, and by the equal segments of the limb. The stamens also project beyond the flower, being inserted in the throat of the corolla, and the filaments grow together at the base; the stigma, is, likewise, curiously dilated into a kind of crescent shape, and it is folded in a very singular manner round the filaments, as if to support the anthers. The most common species of this genus are _N. filicaulis_, _N. calycina_, and _N. gracilis_. The genus _Salpiglossis_ is now confined to one species, _S. sinuata_, so called from its notched or scolloped leaves; all the different kinds being now considered only varieties. The calyx in this species is five-angled and five-cleft, and the corolla is funnel-shaped, the tube being very narrow near the base, and spreading out wider towards the mouth. The limb is five-cleft, and there are five stamens, one being much smaller than the others. The stigma is transverse, with a channel through the centre. _Schizanthus_ is another genus nearly allied to the last, but it is more difficult to give a just idea of it than of any other that I have attempted to describe. All the parts of the flower are irregular. The segments of the calyx are uneven; and the limb of the corolla is cut into a number of irregular lobes. There are only two perfect stamens, but there are two other small ones without any pollen in their anthers, and the rudiments of a fifth. The two perfect stamens are very elastic, springing upwards and discharging their pollen at the slightest touch. The capsule is two-celled, the valves opening at top; and the leaves are bi-pinnatifid. The genera Salpiglossis and Schizanthus have been removed by Dr. Lindley from Solanaceæ, and placed by him in the allied order Scrophularinaceæ, or the Foxglove family. The Henbane (_Hyoscyamus niger_) has the calyx ventricose at the base, and the corolla campanulately funnel-shaped; the limb is five-cleft, and one of the segments is larger than the rest; but the most remarkable part of this plant is the capsule. When the corolla falls, the capsule shrouded in the calyx presents the appearance shown at _a_ in _fig._ 71; and as the seeds ripen, the upper part (as shown at _b_) becomes detached, and opens like a little cap. The leaves are sinuated and semi-decurrent. There are several species of Henbane, one of which (_H. aurea_) has the limb of the corolla deeply cut on only one side. [Illustration: FIG. 71.—HENBANE.]