page_title: Glossary of botanical terms
section_title: G
hierarchical_section_title: Glossary of botanical terms / G
caption_attribution_description: English: Scanning electron microscopy image of stoma, a pore that was found in the epidermis on the bottom of the leaf of Haemanthus albiflos.
context_page_description: This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology.
context_section_description: galbulus
  In gymnosperms, a fleshy cone (megastrobilus); chiefly relates to cones borne by junipers and cypresses, which are often mistakenly called berries.
  gall
  Abnormal outgrowth on external plant tissues, caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites.
  gamete
  A cell or nucleus that fuses with another of the opposite sex during sexual reproduction.
  gametophore
  Specialized structures on the gametophytes of some bryophyte species, for example many species in the order Marchantiales; in such species the gametes are produced on the gametophores, which amount to sex organs.
  gametophyte
  The haploid multicellular phase in the alternation of generations of plants and algae that bears gametes. In bryophytes the gametophyte is the dominant vegetative phase; in ferns and their allies it is a small free-living plant known as the prothallus; in gymnosperms and angiosperms the gametophytes are reduced to microscopic structures dependent on the sporophyte, male gametophytes contained in pollen grains and females contained within the ovules.
  gemma
  an asexual reproductive structure found in liverworts and mosses.
  gene pool
  The complete range of genetic variation found within a population.
  genus
   A group of one or more {{#species|species}} with features or ancestry (or both) in common. Genus is the principal category of taxa intermediate in rank between family and species in the standard nomenclatural hierarchy.
  generic name
  The name of a taxonomic genus, such as Acacia and Eucalyptus.
  genotype
  The genetic make-up of an individual.
  geophilous
  Growing or rooting in the ground.
  germination
  1.  of seeds, describing the complex sequence of physiological and structural changes that occur from resting to growth stage.
  2.  of a pollen grain; production of a pollen tube when contacting a stigma receptive to it.
  3.  of a spore of fungi/bacterium; change of state – from resting to vegetative.
  gibbous (gibbose)
  (of part of an organ) Swollen, usually with a pouch-like enlargement at the base.
  glabrescent
  Becoming glabrous, almost glabrous.
  glabrous
  1.  Lacking surface ornamentation such as hairs, scales or bristles; smooth.
  2.  In lichenology, having no indumentum.
  gland
  A secretory structure within or on the surface of a plant.
  glandular hair
  A hair tipped with a gland.
  glaucous
  Describes the external surface of a plant part that has a whitish covering, in some cases with a blueish cast. Often applied to plants with a woolly or arachnoid surface, but properly referring to pruinose surfaces, meaning those with a waxy bloom. The surface of the young leaves of many eucalypts provide good examples, and so do some xerophytes.
  globose
  Roughly spherical. See also subglobose.
  globulose
  Approximately spherical.
  glochid
  A tiny barbed hair or bristle, e.g. the fine defensive hairs in cactus species such as Opuntia.
  glumes
  bracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost organs of a spikelet (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent).
  glutinous
  Sticky.
  graft
  1.  The artificial union of plant parts.
  2.  A plant shoot suitable for grafting; loosely, a scion, sucker, or branch.
  graft chimaera (sometimes graft hybrid)
  A taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g. Crataegus monogyna + Mespilus germanica) or in front of an abbreviated name (e.g. +Crataegomespilus 'Dardari'). The nomenclature of graft hybrids is governed by the International Code of Nomenclature for Cultivated Plants.
  graminoid
  granular
  (of a surface) Covered with small rounded protuberances.
  grass
  A plant of the family Poaceae.
  grassland
  Low vegetation dominated by grasses.
  groundcover
  1.  Dense vegetation that covers the ground.
  2.  A term applied to describe a plant that covers the soil surface so densely that it smothers all beneath it.
  group
  A formal category equivalent to or below the rank of genu
caption: Scanning electron micrograph of a stoma on the leaf of Haemanthus. The two lip-shaped cells on either side of the gap are the guard cells
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