The leaves of plants, as well as those of trees, differ from one another in the length of the footstalk, and in the breadth or narrowness of the leaf, and the angles and indentations perceptible on its edge. Other differences are also constituted in respect of their smell and blossom. The blossom remains on longer in some of those plants which flower only a little at a time, such as the ocimum,2228 the heliotropium,2229 the aphace, and the onochilis,2230 for example.

(17.) Many of these plants, the same as certain among the trees, never lose their leaves, the heliotropium,2231 the adiantum2232 and the polium,2233 for instance.