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Glossary: H

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