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spore |
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STRUCTURE |
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A simple, usually unicellular, sometimes oligocellular propagule derived by meiotic division of a diploid (2n chromosomes) sporocyte within a sporangium, thus of haploid (n chromosomes) genetic constitution. A spore constitutes the first ontogenetic stage of a gametophytic generation and gives rise to a usually multicellular gametophyte upon germination. Though technically present in seed-bearing plants, by itself it is descriptively significant only in those taxa that do not produce seeds. |
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lip cell |
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STRUCTURE |
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Either of a pair of adjacent, narrow, transversely oriented, thick-walled cells bordering the pore (stomium) of a sporangium. |
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flower |
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STRUCTURE |
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A functionally integrated, complex structure comprising sets of sporophytic and/or associated sterile structures disposed in standard sequence along a common axis; consisting of one or more constituent members each of, in ascending (proximal to distal) order of insertion, perianth (tepals, or else sepals and/or petals), androecium (stamens, staminodes and/or other associated structures), and/or gynoecium (pistils and/or other associated structures), the foregoing all borne laterally from the distal portion (receptacle) of the axis; depending upon the combination of structures present, may be bisexual, staminate only, pistillate only, or sterile; characteristic of and unique to the Magnoliophyta (Angiospermae). When a fertile androecium and gynoecium are both present a flower is termed perfect. When perfect and also with calyx and corolla both present, a flower is termed complete. Both terms are somewhat archaic and of limited descriptive value. |
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midvein |
= midnerve, midrib; < costa, nerve, rib, vein |
STRUCTURE |
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A primary vein that runs longitudinally through the center of a leaf or other basically laminar structure. See also lateral vein, secondary vein, tertiary vein, veinlet. |
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caudex pl. caudices |
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STRUCTURE |
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The short, persistent, thickened, more or less erect, main stem of a perennial plant that otherwise has annual stems. |
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disc 2 var. disk |
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STRUCTURE |
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Collectively, the disc florets of a capitulum (head), or the surface presented by them. |
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secondary root |
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STRUCTURE |
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Any root branch that originates directly or indirectly from a primary root. |
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cilium 1 pl. cilia |
> capillus, hair; >< trichome |
STRUCTURE |
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A hair-like trichome or other surficial process. |
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infructescence 1 |
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STRUCTURE |
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A mature (fruiting) inflorescence (static sense). |
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pinna pl. pinnae |
< leaflet |
STRUCTURE |
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One of the first-order divisions or leaflets of a pinnate frond; in Polypodiophyta. See also pinnule. |
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beak 2 |
= rostrum |
STRUCTURE |
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The inner, horn-like segment of a coronal lobe; esp. in Asclepiadaceae. |
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macrosporocarp (not recommended) |
= megasporocarp |
STRUCTURE |
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A sporocarp that bears only macrosporangia (megasporangia). |
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fruit |
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STRUCTURE |
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Any unitary seed-bearing structure of a flowering plant, consisting of the matured or ripened pistil(s) of one or more flowers along with any other floral or vegetative tissue(s) persisting adnate to them; characteristic of and unique to Magnoliophyta (Angiospermae). |
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axis pl. axes |
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STRUCTURE |
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Any unitary and longitudinally continuous structure that bears laterally the subordinate portion(s), if any, of a plant root or shoot or any subdivision thereof and that represents the main line of structural development and/or symmetry distal to its origin, irrespective of the particular ontogenetic growth pattern involved. See also primary axis. |
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ray floret |
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STRUCTURE |
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A floret that has a zygomorphic corolla, is pistillate (either fertile or sterile) or neuter, and is borne in a radiate capitulum (head) peripheral (proximal) to the disc florets; in Asteraceae (Compositae). |
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gynostegium pl. gynostegia |
< corona |
STRUCTURE |
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An androecial corona, typically consisting of distinct hood- and/or horn-shaped enations that rise above the anthers; esp. in Asclepiadaceae. |
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spore body |
= sporocarp |
STRUCTURE |
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A multicellular structure that bears and more or less encloses several to (usually) many sporangia, the latter often aggregated into sori within it See also megasporocarp (macrosporocarp, not recommended), microsporocarp. |
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husk |
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STRUCTURE |
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A more or less dry, hard or fibrous, simple or compound enclosure or outer layer of a seed, fruit or inflorescence. |
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caudicle |
= translator arm |
STRUCTURE |
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An attenuate end portion by which a pollinium adheres to a pollinating insect, either directly or by means of a terminal viscidium, the latter, when present, sometimes attached by an intervening stipe; esp. in Asclepiadaceae, Orchidaceae. |
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root 1 |
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STRUCTURE |
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Collectively, all those portions of a plant body that are anatomically distinct from the shoot, the component axes not differentiated into nodes and internodes, and branching endogenously. |
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stigma pl. stigmata, stigmas |
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STRUCTURE |
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An exposed, localized portion of a pistil that retains deposited pollen and stimulates its germination, the pollen tubes then growing through or along it toward the ovule(s). |
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disc floret |
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STRUCTURE |
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A floret that has an actinomorphic corolla, is bisexual, functionally staminate, or functionally pistillate, and is borne in a radiate, discoid, disciform, or radiant capitulum (head) interior (distal) to any peripheral series of differing florets that may be present; in Asteraceae (Compositae). |
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flagellum pl. flagella |
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STRUCTURE |
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A very slender whip-like structure that extends from the main body of an antherozoid and, by active undulation, propels the cell through a liquid medium. |
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secondary vein |
< lateral vein |
STRUCTURE |
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A strand belonging to the second order of vasculature in a leaf or other basically laminar structure, except when that is the ultimate order (consisting of veinlets); branching directly from a primary vein or, with undiminished diameter, from another strand of the second order. See also costa, primary vein, rib, tertiary vein, veinlet. |
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cilium 2 pl. cilia |
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STRUCTURE |
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A motile hair- or whip-like structure extending from the surface of a cell. |
