Manettia cordifolia, a very pretty stove-twiner often seen in collections, is very nearly allied to Luculia, differing principally in the shape of the flowers, which in Manettia have a long tube and a very small limb. Bouvardia triphylla and the other species of Bouvardia, and Pinckneya pubescens, belong to this division; and such of my readers as have the living plants to refer to, will find it both interesting and instructive to dissect them and compare the parts of their flowers with the description I have given of Luculia and Cinchona, so as to discover the difference between the different genera; afterwards reading the generic character of each given in botanical works, that they may see how far they were right.
THE GENUS GARDENIA AND ITS ALLIES.
The Cape Jasmine (Gardenia radicans) is a well-known greenhouse plant, remarkable for the heavy fragrance of its large white flowers, which die off a pale yellow, or buff. The calyx has a ribbed tube, and the limb is parted into long awl-shaped segments. The corolla is salver-shaped, that is, it has a long tube and a spreading limb, the limb being twisted in the bud. There are from five to nine anthers, having very short filaments which are inserted in the throat of the corolla. The stigma is divided into two erect fleshy lobes. The ovary is one-celled, but there are some traces of membranes, which would, if perfect, have divided it into from two to five cells. The seeds are numerous and very small. Gardenia radicans is a dwarf plant, which flowers freely when of very small size, and is easily propagated from the readiness with which its stem throws out roots; but G. florida is a shrub five or six feet high, and much more difficult to cultivate. In both species the flowers are generally double, and the petals are of a fleshy substance, which gives the corolla a peculiarly wax-like appearance.
There are many other species, but the two above-mentioned are the most common in British gardens. Burchellia capensis is gene rally considered to belong to this division of Rubiaceæ, though its flowers bear more resemblance to those of Cinchona; and the singular plant called Mussæuda pubescens, the flowers of which are small and yellow, but the bracts are so large and so brilliantly white as to look like flowers; Posoqueria versicolor, an ornamental plant lately introduced, belong to this division.
THE GENUS RONDELETIA AND ITS ALLIES.
Rondeletia odorata, sometimes called R. coccinea, and sometimes R. speciosa, is a very
Fig. 37.—Section of the flower of Rondeletia. fragrant stove shrub, a native of Cuba. The flowers are produced in corymbs, and their botanical construction is shown in the magnified section fig. 37. In this a is the ovary inclosed in a hairy calyx; b shows the limb of the calyx cut into awl-shaped segments; c shows the manner in which the very short filaments of the anthers are inserted in the throat of the corolla; d shows the termination of the dilated receptacle which lines the tube of the corolla; and e the segments of the limb. I have given the section of this flower, that my readers may compare it with the section of the flower of the Cinchona in fig. 36,
