It ought to have been noticed that the character of serration, within reserved limits, is essential to an Apolline leaf, and absolutely refused by an Arethusan one.
III. Dryad.—Of the ordinary leaf tissue, neither manifestly strong, nor admirably tender, but serviceably consistent, which we find generally to be the substance of the leaves of forest trees. Typically represented by those of the oak.
IV. Abietine.—Shaft or sword-shape, as the leaves of firs and pines.
V. Cressic.—Delicate and light, with smooth tissue, as the leaves of cresses, and clover.
VI. Salvian.—Soft and woolly, like miniature blankets, easily folded, as the leaves of sage.
VII. Cauline.—Softly succulent, with thick central ribs, as of the cabbage.
VIII. Aloeine.—Inflexibly succulent, as of the aloe or houseleek.
No rigid application of these terms must ever be attempted; but they direct the attention to important general conditions, and will often be found to save time and trouble in description.
IV. The Flower.