graft. A cutting inserted in another plant for the purpose of having it grow there.
gymnosperm (“naked seed”). A name applied to a group of plants (pines, spruces, cedars, and the like) in which the seeds are not contained in an ovary.
head. A very dense globular or oblong flower-cluster in which the outer flowers open first; often applied to any dense flower-cluster.
herb. A plant that never becomes woody and that dies to the ground, or dies entirely, in winter.
hilum. The scar or spot where the seed was attached to its stalk.
hip. The fruit of the rose, which is a hollowed torus containing the dry fruits or “seeds.”
homologous. Related to, or with, in origin or structure. Thus, a tendril of grape is homologous with a branch; a tendril of grape is analogous to a tendril of pea (similar in function), but not homologous, for one represents a branch (or flower-cluster) and the other represents a leaf.
host. A plant or animal on which another organism grows or feeds.
hypha (plural hyphæ). The threads of the mycelium of a fungus.
hypocotyl. The stem or internode below the seed-leaves.