The broadest leaves are those of the fig, the vine, and the plane; while those of the myrtle, the pomegranate, and the olive are narrow. The leaf of the pine and the cedar is fine and resembles hair, while that of the holly and one variety of the holm oak[1] is prickly-indeed, in the juniper, we find a thorn in place of a leaf. The leaf of the cypress and the tamarisk[2] is fleshy, and that of the alder is remarkable for its thickness.[3] In the reed, the willow, and the palm,[4] the leaf is long, and in the latter tree it is double as well: that of the pear is rounded, and it is pointed in the apple.[5] In the ivy the leaf is angular, and in the plane divided.[6] In the pitch-tree[7] and the fir the leaf is indented like the teeth of a comb; while in the robur it is sinuous on the whole of the outer margin: in the bramble it has a spiny surface. In some plants the leaf has the property of stinging, the nettle for instance; while in the pine,[8] the pitch-tree, the fir, the larch, the cedar, and the holly, it is prickly. In the olive and the holm-oak it has a short stalk, in the vine a long one: in the poplar the stalk of the leaf is always quivering,[9] and the leaves of this tree are the only ones that make a crackling noise[10] when coming in contact with another.

In one variety of the apple-tree[11] we find a small leaf protruding from the very middle of the fruit, sometimes, indeed, a couple of them. Then, again, in some trees the leaves are arranged all round the branches, and in others at the extremities of them, while in the robur they are found upon the trunk itself. They are sometimes thick and close, and at others thinly scattered, which is more particularly the case where the leaf is large and broad. In the myrtle[12] they are symmetrically arranged, in the box, concave, and, upon the apple, scattered without any order or regularity. In the apple and the pear we find several leaves issuing from the same stalk, and in the elm and the cytisus[13] they are covered with ramified veins. To the above particulars Cato[14] adds that the leaves of the poplar and the quercus should not be given to cattle after they have fallen and become withered, and he recommends the leaves of the fig,[15] the holm-oak, and the ivy for oxen: the leaves, too, of the reed and the laurel are sometimes given them to eat. The leaves of the service-tree fall all at once, but in the others only by degrees. Thus much in reference to the leaves.