RAMUS, in general, denotes a branch of any thing, as of a tree, an artery, &c. In the anatomy of plants it means the first or lateral branches, which go off from the petiolum, or middle rib of a leaf. The subdivisions of these are called surculi; and the final divisions into the most minute of all, are by some called capillamenta; but both kinds are generally denominated surculus.