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Term	Definition
Hetero-	A prefix meaning different or other.
Heteroblastic	Referring to a plant with juvenile forms that are morphologically distinct from adult forms; often used to describe leaves changing from compound to simple as the plant passes from juvenile to adult.
Heterochlamydeous	Referring to a flower with differentiated calyx and corolla; same as biseriate perianth. Compare with monochlamydeous.
Heterogamous	Having flowers of two or more different types; e.g., the heads of certain Asteraceae with both ligulate and disk flowers.
Heteromorphic	Referring to structures or organs within a species or individual that differ in form or size; e.g., the simple juvenile and pinnately compound leaves of Syagrus inajai (Arecaceae). Compare with dimorphic and monomorphic.
Heteromorphic stamens	Stamens of two distinct types; one type usually bears fertile pollen and the other type bears sterile or fodder pollen; e.g., Lecythis zabucajo (Lecythidaceae) and species of Senna (Fabaceae).
Heterophylly (heterophyllous)	Referring to species or individuals with leaves that differ in size or shape. See heteromorphic.
Heterospory (heterosporous)	Producing two different kinds of spores; e.g., those giving rise to the microgametophytes and megagametophytes of Selaginella, Isoetes, and the flowering plants and the
Heterostyly (heterostylous)	A condition in which the style and stamen lengths vary among individuals of the same species; e.g., in Coussarea racemosa (Rubiaceae), with flowers with long styles and short stamens and flowers with short styles and long stamens in different trees of the same population. The long-styled flowers are called pin flowers and the short-styled flowers are called thrum flowers.
Heterótrofa, heterotrófica	Se refiere a las plantas que son incapaces de sintetizar los compuestos orgánicos a partir del substrato inorgánico. Opuesto a autótrofa o autotrófica
Heterotroph (heterotrophic)	Unable to synthesize organic compounds from inorganic substrates, i.e., this kind of plant does not photosynethesize and is not green in color because it lacks chlorophyll.
Hierba	Planta no leñosa. Las herbáceas por lo general son plantas pequeñas, pero también pueden alcanzar un gran tamaño; por ejemplo, la papaya (Carica papaya L.).
Higher order leaf venation	Referring to venation levels in the leaves above the tertiary veins.
Higher order venation	All venation smaller in diameter than tertiary venation.
Hilum (hilar)	A scar on the seed indicating where the funicle was attached.
Hipantio	Es un tubo floral constituido por las partes fusionadas del perianto, a veces incluye tejidos del receptáculo. El tubo puede estar libre del ovario, como en las flores períginas, o puede estar fusionado al ovario, como en las flores epíginas
Hipocarpo	Pedicelo engrosado que sostiene al fruto de Anacardium (Anacardiaceae). También se lo conoce como fruto falso o pseudofruto.
Hippocrepiform	Horseshoe-shaped.
Hippuriform	Shaped like a horse’s tail; e.g., the inflorescences of species of Oenocarpus (Arecaceae).
Hirsute (diminutive = hirtellous)	With rough or coarse hairs.
Hispid (diminutive = hispidulose)	With dense, stiff trichomes.
Hoja	Estructura expandida donde se produce la fotosíntesis, usualmente está compuesta por un peciolo y una lámina
Hoja compuesta	Se refiere a una hoja que está dividida en varias o muchas unidades laminares más pequeñas. Opuesto a hoja simple
Hoja imparipinnada	Se refiere a una hoja compuesta que posee un foliolo impar en la porción distal. Comparar con paripinnada
Hoja paripinnada	Se refiere a una hoja compuesta que posee un par de foliolos en la porción distal. Equivalente a bipinnada. Comparar con imparipinnada
Hoja simple	Se aplica a una hoja que no está dividida en unidades laminares más pequeñas. Opuesto de compuesto
Hoja unifoliolada	Se refiere a una hoja que aparenta ser simple, pero se considera que ha evolucionado desde algún ancestro de hojas compuesta. Frecuente en las Fabaceae
Hojas alternas	Se refiere a la disposición de las hojas, cuando están solitarias en cada nudo a lo largo de un eje; las hojas pueden ser simples o compuestas. Comparar este término con la definición de hojas opuestas y verticiladas.
Holdfast	See hapter.
Holoparasite	An achlorophyllous plant that derives all of its nutrition from its host; e.g., species of Balanophoraceae and Rafflesiaceae.
Holotype	A single specimen designated by the author of the species to represent that species. If there are duplicates of that specimen, they are called isotypes.
Homo-	A prefix meaning “the same.”
Homoecy (adj. = homoecious)	A species that bears only bisexual flowers on each plant.
Homoecy (homoecious)	Referring to a species that bears only bisexual flowers on each plant.
Homogamous	Possessing flowers of one kind; e.g., the heads of certain Asteraceae with only disk flowers; referring to flowers in which the anthers release pollen at the same time as the stigma(s) is (are) receptive.
Homophyllous	See isophyllous.
Homoptera	The order of insects including the cicadas and leaf hoppers, the species of which are sometimes phytophagous.
Homospory (homosporous)	Producing a single kind of spore; e.g., as in bryophytes, Lycopodium, and most but not all species of ferns.
Homostyly	A condition in which the style and stamen lengths are more or less the same in all individuals of a species. Opposite of heterostyly.
Honey guide	Same as nectar guide.
Hood	One of five hollow chambers of the corona of some species of Apocynaceae subfamily Asclepiadoideae; see androecial hood.
Hood-shaped	See cucullate.
Hoop mark	A raised ring caused by bud scale scars that may partially or completely encircle the trunk of a tree.
Horn	An flora appendage shaped like an animal’s horn; e.g., the horn of the corona of Apocynaceae subfamily Asclepiadoideae.
Host	In botany, a plant upon which another plant or an animal feed on or parasitizes; e.g., many trees are hosts for parasitic plants such as mistletoes.
Host-specific	Referring to an animal that lives on or feeds on a single host species.
Hot spot	A concept first developed by Norman Myers in which priority for conservation is based on the idea that it will be too costly to protect all species throughout the world; thus, Myers suggested that areas with high degrees of endemism and which are under going rapid lost of habitat should be given priority for protection. As many as 44% of all species of vascular plants and 35% of all species in four vertebrate groups are confined to 25 hotspots comprising only 1.4% of the land surface of the Earth. The idea of this strategy is to put maximum effort into protecting these areas. See Myers, N. et al. 2000. Biodiversity hotspots for conservation priorities. Nature 403: 853-858.
Humifuse	Referring to a growth form in which the plant is spread out over the ground.
Hummack	A small mound; e.g., a mound rising above the waters of a swamp.
Humus	Referring to a layer of topsoil rich in decaying organic material.
Hyaline	Very thin almost to the point of being colorless and transparent; often applied to leaf, sepal, or petal margins.
Hybrid (hybridization)	The result of a cross between genetically dissimilar individuals, most commonly referring to crosses between two different species.
Hydathode	A structural modification, usually in leaves, that permits the release of water through an opening in the epidermis.
Hydrophobic	Not combining or mixing well with water; e.g., the pollen grains of Cymodoceaceae.
Hydropote	In the Myrsinaceae, a multicellular, epidermal structure, often of leaves, serving for the absorption of water and mineral salts. When young, hydropotes consist of a basal stalk and a group of cap cells, but at maturity the superficial structure breaks off and the remaining depression often regulates water as a hydathode.
Hygrochastic	Referring to a type of plant movement caused by the absorption of water; e.g., the opening of capsular fruits as the result of taking in moisture from the air.
Hygroscopic	Readily taking up and retaining moisture; structures sometimes change in position as a result of alternating gain and loss of water.
Hypanthium	A floral tube made up of fused parts of the perianth and sometimes including receptacular tissue. The tube may be free from the ovary as in perigynous flowers or it may be fused to the ovary as in epignynous flowers.
Hypanthium	A floral tube made up of fused parts of the perianth and sometimes including receptacular tissue. The tube may be free from the ovary as in perigynous flowers or it may be fused to the ovary as in epignynous flowers.
Hypha (plural = hyphae)	The filaments of a fungus that combine to form the above ground mushroom and the below ground part of the fungus, the latter are analagous to the roots of vascular plants. In a mycorrhizal relationship, the hyphae attach to roots of plants and mediate the movement of carbohydrates to the fungus and minerals from the fungus to the plant.
Hypocarp	The swollen pedicel that subtends the fruit of Anacardium (Anacardiaceae). Also called the cashew apple.
Hypochile	The basal portion of a complex lip in Orchidaceae.
Hypocotyl	The part of the main axis of a seed embryo or a very young seedling found below the cotyledonary node.
Hypocotyl	The part of the main axis of a seed embryo (or a very young seedling) found below the cotyledonary node. The roots grow from the hypocotyl.
Hypocrateriform	Referring to the shape of a sympetalous corolla in which the tube is slender and the lobes are abruptly spreading and flat. Same as salverform which is preferred over hypocrateriform.
Hypogeal germination	A type of seed germination in which the cotyledons are retained below the ground.
Hypogeous fruits	Immature fruits that penetrate the ground where they develop to maturity, the best examples are the hypogeous fruits of the peanut (Arachis hypogaea) and other legumes.
Hypogynium	A disc or cuplike structure below the ovary of some Cyperaceae.
Hypogynous bristle	Hairlike filaments arising from the base of the achene in some species of Cyperaceae.
Hypogynous ovary	Referring to a flower in which 1) the sepals, petals, and stamens are free from one another and arise from beneath the ovary, e.g., the flowers of Ranunculaceae or 2) bristles or other structures as well as stamens arise from below the ovary, e.g., the bristles of some species of Cyperaceae and the modified bracts of species of Poaceae. Compare with epigynous and perigynous.
Hypopeltate anther	Referring to an anther with the filament attached above the base and with the part of the anther that is prolonged downward facing away from the center of the flower.
Icthyochory (icthyochorous)	Referring to the process by which diaspores are moved from one place to the other (dispersed) by fish. Same as fish seed dispersal.
Igapó	A Portuguese term referring to forest growing in areas periodically indundated by acidic, black-colored water (also called white water).
Igapó	A Portuguese term referring to forest growing in areas periodically indundated by acidic, black-colored water (also called white water). See Prance (1979) for more information about forests subjected to inundation in Amazonia. See Prance (1979) for more information about forests subjected to inundation in Amazonia.
Imbibition lid	In the Cannaceae, a lid on the raphe of the seed that covers a pore through which water passes into the seed.

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