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sapwood |
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STRUCTURE |
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That portion of the wood (xylem) of a stem or root whose cells are still living and functional; concentric about the heartwood once the latter has begun to form. |
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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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hypogynium pl. hypogynia |
= gynophore; < stalk, stipe (broad sense, not recommended) |
STRUCTURE |
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The basal portion of an ovary when constricted and stalk-like above the level of perianth insertion, bearing the main body of the pistil at its summit; in Cyperaceae. |
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turion |
< sucker |
STRUCTURE |
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A scaly sucker. |
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rostrum 1 pl. rostra |
= beak |
STRUCTURE |
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A relatively long, tapering, more or less rigid and pointed enation or termination. |
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knee root |
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STRUCTURE |
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A specialized secondary root of a wetland tree, a portion of which projects above mean water level and appears to bend as a leg does at the knee, its distalmost portion being anchored in the substrate beneath the water. The knee of the root is commonly regarded as a conduit for gas exchange between root interior and atmosphere, a function whose need is posited on the basis of the highly anaerobic and saturated conditions prevailing in wetland substrates. |
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cross-vein |
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STRUCTURE |
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A relatively short, secondary or higher-order vein that runs directly between two veins of the next lower order, intersecting them more or less perpendicularly. |
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prophyll(um) pl. prophylls, prophylla |
= bracteole, bractlet; < bract |
STRUCTURE |
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A second- or higher-order bract within, and subtending some portion of, an aggregate branching structure, especially when subtending a flower. |
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rhizome |
= rootstock |
STRUCTURE |
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An underground, usually horizontal stem, often superficially resembling a root but easily distinguished by the presence of nodes, from which it branches exogenously to produce the aboveground portion(s) of the shoot. |
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adventitious bud |
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STRUCTURE |
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A vegetative or floral bud that arises directly from a root or from some site on a shoot other than a leaf axil or stem apex. |
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lenticel |
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STRUCTURE |
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A specialized, anatomically distinct structure within the periderm of a stem, consisting of comparatively spongy, sometimes suberized tissue distinct from others of the periderm; extending radially through the periderm and visible as a circular to elongate discontinuity in the color, texture, and/or relief of the outer surface of the stem; serving as a conduit for gas exchange between the stem interior and the atmosphere. |
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cycle |
= series, verticil, whorl |
STRUCTURE |
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A set of three or more lateral structures that are inserted around an axis at the same level. |
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ear |
= auricle |
STRUCTURE |
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A small, rounded, lateral lobe at the base of a laminar structure, lying in more or less the same plane as the remainder of the lamina. |
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rostrum 2 pl. rostra |
= beak |
STRUCTURE |
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The inner, horn-like segment of a coronal lobe; esp. in Asclepiadaceae. |
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mentum pl. menta |
= column foot |
STRUCTURE |
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A lateral, often nectariferous protrusion from the proximal portion of a column, opposite the labellum, projecting in front of the rest of the flower; in Orchidaceae. |
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mericarp |
= coccus |
STRUCTURE |
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One of the segments of a dehisced schizocarp; usually one-seeded and itself indehiscent. |
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rhizophore |
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STRUCTURE |
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A stem branch that bears no leaves and from which roots eventually arise; esp. in Selaginellaceae. |
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sporangiophore |
< stalk |
STRUCTURE |
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A stalk that bears one or more sporangia. |
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toothlet |
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STRUCTURE |
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A diminutive tooth (dens). See also sawtooth, sawtoothlet, scallop (crena), scalloplet (crenule). |
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lip |
= labium; > labellum |
STRUCTURE |
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Any substructure that resembles a lip, especially a portion of a perianth, calyx or corolla. |
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veinlet |
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STRUCTURE |
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A strand belonging to the ultimate (least in diameter) order of vasculature in a leaf or other basically laminar structure when that order consists of strands ending freely within areoles and/or connecting distally by pairs across areoles; absent in some taxa. See also costa (rib), lateral vein, midvein (midnerve, midrib), primary vein, secondary vein, tertiary vein, vein (nerve). |
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adventitious root |
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STRUCTURE |
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A root that arises laterally from some part of a shoot, often from the lower portion of a main stem. |
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articulation |
= joint |
STRUCTURE |
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A distinct, relatively narrow zone of demarcation between adjacent main portions of an elongate structure, often thicker than the rest of the structure and sometimes a site of eventual abscission. |
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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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sperm |
> antherozoid, spermatozoid |
STRUCTURE |
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A male gamete. |
