Malesia: a phytogeographic region; including the Malay Peninsula, Malaysia, the Philippines, Indonesia and New Guinea.
mallee: (1) a growth form in which many stems arise from a lignotuber, usually applied to eucalypts; (2) of a plant community dominated by mallee eucalypts.
mangrove: a shrub or small tree growing in salt or brackish water and often with pneumatophores or aerial roots.
marcescent: withering without falling off.
marginal: (1) at or very close to the margin; (2) of placentation, with the placenta along the margin of a simple ovary, as in many legumes, Fig. 13 A.
maritime: belonging to the sea; confined to the sea-coast.
marsh: a waterlogged area; swampy ground without trees.
mealy: covered with coarse flour-like powder.
medifixed: attached by or at the middle, e.g. of anthers, attached to the filament at the middle of the connective.
megasporangium: a sporangium producing megaspores, = ovule in flowering plants.
megaspore: the spore in heterosporous plants that gives rise to a female gametophyte and is generally larger than the microspore; the spore usually not shed but remaining on the parent plant and developing in situ. cf. microspore.
megasporophyll: a specialised leaf upon (or in the axil of) which one or more megasporangia are borne. cf. microsporophyll.
meiosis: the two-stage division of a diploid nucleus in which the genetic recombination occurs and the number of chromosomes characteristic of the species is halved prior to the production of the sexual gametes; this process takes place once in every sexual life cycle.
membranous: thin and translucent.
mentum: a chin-like extension at the base of some orchid flowers formed by the column foot and the bases of the lateral sepals.
mericarp: one segment of a fruit that breaks at maturity into units derived from the individual carpels, sometimes called a coccus. Fig. 18 H & P. See schizocarp.
meristem: a growing region of a plant in which cells divide to produce new cells.
-merous: a suffix indicating that the number of parts in each floral whorl is divisible by the same basic number, e.g. a 5-merous flower is one with the number of sepals, petals and stamens divisible by 5; e.g. 5 sepals, 10 or 5 petals, and 5, 15 or 20 stamens. The number of carpels and their styles or stigmas often does not conform to the basic number.
mesic: requiring abundant water.
mesocarp: the fleshy part of the wall of a succulent fruit; the middle layer of the pericarp in a drupe.
mesomorphic: soft and with little fibrous tissue, but not succulent. cf. scleromorphic.
mesophyll: photosynthetic tissue of a leaf; of vegetation, characteristic of moist habitats and with soft, fairly large leaves predominating.
microphyllous: having small leaves that are usually hard and narrow.
micropyle: the small canal through the integuments (outer layers of tissue) of an ovule, usually at the point furthest away from the funicle (ovule stalk), persisting as a pore in the seed coat.
microspecies: segregate species of a larger species or species-aggregate, e.g. see Rubus fruticosus.
microsporangium: the sporangium producing the microspores, within the anthers in angiosperms.
microspore: the spore in heterosporous plants that gives rise to a male gametophyte and is generally smaller than a megaspore; microspores are shed at maturity. cf. megaspore, pollen.
microsporocarp: a body containing the microsporangium, e.g. as in some ferns.
microsporophyll: a specialised leaf upon (or on the axil of) which one or more microsporangia are borne
midrib: term applied to the midvein or primary vein, especially when it is prominently raised or depressed.
midvein: the primary vein which runs from the base to the apex of the lamina, usually the most prominent vein, from which arise the secondary or lateral veins.
minute: very small, usually less than 1 mm long.
mitra: a pointed cap or hood.
monadelphous: of stamens, with their filaments fused into one group, as in many Malvaceae. Fig. 20 G. cf. diadelphous.
moniliform: of a pod or other organ: constricted , so as to resemble a necklace of beads; e.g. hairs, Fig. 15 E.
mono-: a prefix, one: as in monotypic, a genus with 1 species.
monochasium: a cyme with the branches arising singly. Fig. 17 E. cf. dichasium.
monochlamydeous: of a flower, having only one whorl of perianth parts. cf. dichlamydeous.
monocotyledons: a major group of angiosperms, characterized by the embryo usually having one cotyledon (seed leaf). cf. dicotyledons.
monoecious: having male and female flowers on the same plant.
monophyletic: derived from a single ancestral line. cf. polyphyletic.
monopodial: with a persistent terminal growing point producing many lateral organs progressively. cf. sympodial.
monotypic: of a genus, having only one species. cf. unigeneric.
motile: actively moving; self-propelled.
mucilage: a slimy, gummy substance sometimes secreted by hairs or glands. adj. mucilaginous.
mucro: a sharp, usually suddenly constricted, apical point.
mucronate: having a mucro. Fig. 6 K.
mucronulate: a small mucro on obtuse apex.
multicellular hairs: hairs consisting of more than 1 cell.
multiple fruit: a cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as in Moraceae. Fig. 18 Y & Z. e.g. syncarp, syconium. cf. aggregate fruit.
muricate: of a surface, rough with pointed protuberances or short hard tubercles. Fig. 16 B.
muriculate: minutely muricate, rough with minute, short, hard points.
muticous: blunt, awnless, lacking a point.
mycorrhiza: a symbiotic association between a fungus and a plant root.
naked: of flowers, without a perianth; of sporangia, not covered with an indusium; of seeds, not enclosed in an ovary, exposed on the surface of a sporophyll.
native: naturally occurring in the area, but not necessarily confined to it. cf. endemic.
naturalized: originating elsewhere but established and reproducing itself as though native to the area.
nectar: a more or less sweet fluid secreted from a specialized gland or nectary.
nectary: a gland that secretes nectar.
neotype: a specimen selected to serve in place of a holotype where none of the material to which the name was originally applied is known to have been preserved.
nerve: a vein, usually applied to rather straight and strong veins.
net veins (reticulate): forming a network or reticulum; e.g. of veins, Fig. 9 H.
nocturnal: of flowers, opening only at night. cf. diurnal.
node: the level of a stem at which one or more leaves arise.
nodulose: with small swellings or knobs.
nomenclature: the names and naming of things; often restricted to the correct usage of scientific names in taxonomy.
nom. cons.: (nomen conservandum, Latin) a name for a taxon that has been formally accepted as the correct name even though it is contrary to the usual principles of botanical nomenclature.
nom. illeg.: (nomen illegitimum, Latin) a name which, at its time of publication, was superfluous (because the taxon to which it was applied had already been named) or had already been applied to another plant.
nom. nud.: (nomen nudum, Latin) a name not published in accordance with the principles of botanical nomenclature (usually without a diagnosis or description of the entity to which it applies and without reference to either); such a name should not be used.
non: (Latin) not of.
nut: a dry indehiscent one-seeded fruit formed from two or more carpels. Fig. 18 T.
ob-: a prefix: the other way around, as in obovate.
obconical: cone-shaped but attached to the narrower end.
obcordate: heart-shaped but attached at the pointed end, e.g. of a leaf lamina
oblanceolate: a 2-dimensional shape, lanceolate but broadest in the upper third. Fig. 5 L. cf. lanceolate.
oblate: almost circular, but with breadth slightly greater than the length. Fig. 5 F.
obligate: of parasites, unable to survive without the host. cf. facultative.
oblique (asymmetric): of a leaf, leaf base or other organ, having the sides unequal. Fig. 7 E.
obloid: a 3-dimensional shape, almost globose but with breadth slightly greater than the length.
oblong: a 2-dimensional shape, rectangular with length greater than breadth. Fig. 5 C.
obovate: a 2-dimensional shape, ovate but broadest above the middle. Fig. 5 M.
obpyriform: pear-shaped but broadest above the middle.
obsolescent: non-functional but not reduced to a rudiment.
obsolete: reduced to a rudiment, or completely lacking.
obtuse: blunt or broadly rounded, the converging edges separated by an angle greater than 900, e.g. of an lamina apex (Fig. 6 E) or of a lamina base (Fig. 7 C).
occluded: closed, in the sense of fused as in the leaves of Dianella species.
ocrea (ochrea): a sheath formed from two fused stipules encircling the node in Polygonaceae. Fig. 4 H. pl. ocreae.
oil glands (oil dots): small structures embedded in a leaf or other organ, secreting a volatile oil, mostly visible as small translucent dots (hand lens needed) against a strong light; usually making the organ aromatic when crushed.
one-foliolate (1-foliolate, unifoliolate): a compound leaf reduced to a single leaflet, usually recognized by the articulated or jointed ‘petiole’, which is in fact a petiole plus a petiolule. Fig. 3 I.
ontogeny: the development of a single organism, i.e. the sequence of stages through which it passes during its lifetime.
open forest: a forest dominated by trees with relatively narrow isobilateral leaves forming sparsely foliaged crowns (usually species of eucalypts); the forest canopy is sparse and often not continuous, allowing sunlight to reach the ground within the forest. cf. closed forest.
operculum (calyptra): a cap-like covering or lid of some flowers or fruits that becomes detached at maturity by abscission; e.g. (1) the cap on the buds of eucalypts, (2) the lid of circumsciss capsules.
opposite: inserted at the same level, as in leaves on the opposite side of the stem (Fig. 2 C & D), or in flowers the floral parts on the same radius. cf. alternate.
order: a taxonomic group consisting of one or more closely related families.
orbicular: orb-shaped, strictly a 3-dimensional shape but often used for a 2 dimensional circular shape, as for leaves (orbiculate).
orifice: a small opening or aperture.
orthotropous: of an ovule, with the body straight and erect so that the micropyle is terminal and the funicle attached at the base; embryo sac straight Fig. 21 A & B. cf. amphitropous, anatropous, campylotropous, hemitropous.
ortho-: a prefix: straight.
orthostichous: arranged in regular vertical rows on a stem or axis. cf. distichous.
orthotropic: mode of growth of vertical branches or leading shoots, especially in conifers where lateral (plagiotropic) branches may have different morphology.
osmophore: a scent-producing gland.
ostiole: an opening or pore, e.g. at the apex of a fig (fruit of Ficus species). adj. ostiolate
ovary: the basal portion of a carpel or a group of fused carpels in which one or more ovules are enclosed, and which after fertilization develops into the fruit.
ovate: a 2-dimensional shape, with the length 1–3 times the breadth, and broadest below the middle. Fig. 5 J.
ovoid: the 3-dimensional equivalent of ovate; egg-shaped.
ovule: a structure in seed plants within which one or more megaspores are formed, and which after fertilization develops into the seed.
ovuliferous: bearing ovules (e.g. applied to scales in a megasporangiate cone in gymnosperms).
ovulode: a sterile ovule.
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