A vine in its broadest sense is any plant with a weak stem which supports itself by climbing on neighbouring plants, walls, or other supports. Of this group of plants the grapevine is the most famous, and the most commercially important. (In this work the word vine is used to mean the grapevine.) There are various forms of climbing vines which rely on different mechanisms for attachment. The so-called ramblers rest on each other’s plants and some, as for roses, have spines to help adhesion. The grapevine is one of the so-called tendril climbers with tendrils on the stem; the garden pea has leaf tendrils.