Glossary: H
- H
- Species is listed as Historical (not observed for at least 20 years).
- habit
- The overall shape and bearing of a plant.
- habitat
- The environment in which a plant normally grows.
- hair
- A soft, slender, straight or branched outgrowth of the epidermis, often only one cell thick.
- halophyte
- Plant adapted to living in saline habitat.
- hastate
- Leaf base consists of two triangular lobes pointed outward.
- haustorium
- The sucker by which a parasitic plant anchors itself on a host plant.
- head
- Short, dense inflorescence (synonym: "capitulum").
- height
- Vertical distance (in meters) from the base of a plant at ground-level to the uppermost growing tip.
- helical
- Coiled like a spring.
- helix
- Coil.
- hemiparasite
- A parasitic plant that possesses chlorophyll and can photosynthesize but also obtains nutrition from its host plant.
- herb
- A plant that dies back to the ground at the end of each growing season (non-woody).
- herbaceous
- Not woody; having the texture of a leaf.
- herbage
- Stems and leaves (above the ground).
- hesperidium
- A partitioned berry with a leathery, removable rind (such as an orange).
- heterophyllous
- Producing two or more types of distinct leaves.
- hilum
- The scar at the point of attachment of a seed.
- hirsute
- With stiff, coarse, curving hairs.
- hispid
- With long, stiff hairs or bristles.
- historical
- Not seen for several years.
- hollow pith
- Interior of branchlet has little or no tissue.
- holoparasite
- A parasitic plant that lacks chlorophyll and depends entirely on a host for its nutrition.
- homophyllous
- With leaves and bracts all of similar size.
- hood
- A covering structure with the top and sides curving inward.
- horn
- A slender process at the base of the corona of some Apocynaceae.
- hydathode
- A structure near a leaf margin that discharges water.
- hydrophilous
- Water-pollinated.
- hypanthium
- A cup- or tube-shaped section of tissue in a flower formed from the fusion of the basal portion of the sepals, petals, and stamens; especially common in many species of rose (Rosa).
- hypocotyl
- The part of the stem of a young seedling between the radicle (embryonic root) and the cotyledon (embryonic leaf).
- hypogynous
- With a superior ovary that lacks a hypanthium.