Of some plants the fruits943 are in the earth, of others both in the earth and out of it, and of others, again, out of the earth solely. Some of them increase as they lie upon the ground, gourds and cucumbers, for instance; the same products will grow also in a hanging position, but they are much heavier even then than any of the fruits that grow upon trees. The cucumber, however, is composed of cartilage and a fleshy substance, while the gourd consists of rind and cartilage: this last is the only vegetable production the outer coat of which becomes of a ligneous nature, when ripe. Radishes, turnips, and rape are hidden in the earth, and so, too, are elecampane,944 skirrets,945 and parsnips,946 though in a different manner. There are some plants, again, to which we shall give the name of “ferulaceous,” anise947 and mallows, for instance; indeed, we find it stated by some writers that in Arabia948 the mallow becomes arborescent at the sixth month, so much so, in fact, as to admit of its being used for walking-sticks. We have another instance, again, in the mallow-tree of Mauretania, which is found at Lixus, a city built upon an æstuary there; and at which spot, it is said, were formerly the gardens of the Hesperides, at a distance of two hundred paces from the Ocean, near the shrine of Hercules, more ancient, tradition says, than the temple at Gades. This mallow-tree949 is twenty feet in height, and of such a thickness that there is not a person in existence who is able with his arms to span its girth.
In the class of ferulaceous plants we must include hemp950 also. There are some plants, again, to which we must give the appellation of “fleshy;”951 such as those spongy952 productions which are found growing in damp meadows. As to the fungus, with a hard, tough flesh, we have already953 made mention of it when speaking of wood and trees; and of truffles, which form another variety, we have but very recently given a description.954