Besides the plants contained in these four tribes, there are several other genera which some botanists place in Solanaceæ, and others in Scrophularineæ; and among these may be mentioned Franciscea, Browallia, and Anthocercis. In the former of these genera the flowers are small, the corolla is salver-shaped, and the calyx, which is permanent, is inflated and smooth. In Browallia, the calyx is strongly ten-ribbed, and the corolla has an oblique limb; and in both genera there are only four stamens, two of which are longer than the others. In Anthocercis there are four perfect stamens and the rudiments of a fifth. The corolla is not folded in the bud, but has a regular, star-like limb. CHAPTER X. THE ORDER URTICACEÆ: ILLUSTRATED BY THE COMMON NETTLE; THE HOP; THE HEMP; THE PELLITORY OF THE WALL; THE BREAD-FRUIT TREE; THE JACK-TREE; THE COW-TREE OR PALO DE VACCA; THE UPAS OR POISON-TREE OF JAVA; THE MULBERRY; THE PAPER MULBERRY; THE OSAGE ORANGE, OR MACLURA; THE COMMON FIG; FICUS SYCAMORUS; THE BANYAN TREE; THE INDIAN-RUBBER TREE; AND FICUS RELIGIOSA. This very large order is divided into two distinct tribes, which many botanists make separate orders; the one embracing the herbaceous species with watery juice, and the other the ligneous species, all of which have their juice milky. The botanical construction of the flowers is, however, strikingly alike in all, from the nettle and the humble pellitory of the wall, to the fig and bread-fruit tree. In all the genera, the male and female flowers are distinct, that is to say, some of the flowers have only stamens, and the others only a pistil; the latter, of course, being the only ones that produce seed. None of the flowers have any corolla; and in all the male flowers, the stamens, which are erect at first, spring back with elasticity to discharge their pollen, and afterwards remain extended. The seeds of all are enclosed in nuts: though the eatable part varies, being in some the dilated receptacle, as in the Bread-fruit and the Fig, and in others the metamorphosed calyx, as in the Mulberry. Many of the genera have one or two species which produce eatable fruit, though the fruit of the other species of the same genus is unwholesome; an anomaly rarely to be met with in any other order except Solanaceæ; and though the milky juice of most of the plants is poisonous, it affords in one species, the Cow-tree, wholesome food. TRIBE I.—URTICACEÆ. All the plants contained in this tribe agree with the common Nettle in yielding a watery juice when broken; in their flowers having no corolla; in the male and female flowers being distinct; in the stamens being first erect, but springing back when they discharge their pollen, and remaining extended; and in their fruit being a nut. Most of them also agree in having rough leaves and angular stalks, the fibres of which are so tenacious as to be capable of being spun. [Illustration: FIG. 72.—NETTLE (_Urtica dioica_).]