embryo sac |
< megagametophyte |
STRUCTURE |
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The multinucleate generative cell of an ovule, within which fertilization and zygote formation occur; resulting from meiotic division of a megaspore mother cell within the nucellus, and thus genetically haploid; its contents generally considered to represent an evolutionarily reduced gametophyte. |
haft |
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STRUCTURE |
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The narrow portion of a structure that is notably constricted. |
primary root |
> taproot |
STRUCTURE |
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The one, central root directly basal to a shoot, developing directly from the embryonic radicle; the first-formed root of a plant, being the only one truly central in nature (i.e., belonging to the original central axis of the plant). All other roots of a plant develop subsequently and are lateral in nature. The primary root may be permanently dominant, developing into a taproot; otherwise it may be transitory or become functionally subordinate, with secondary and/or adventitious roots becoming dominant. |
main stem |
= primary stem; > bole, trunk |
STRUCTURE |
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The one, or any of the more than one, first-order stem(s), or first-order portion(s) of the collective stem, of a shoot. |
primary stem |
= main stem; > bole, trunk |
STRUCTURE |
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The one, or any of the more than one, first-order stem(s), or first-order portion(s) of the collective stem, of a shoot. |
stomatal pore 1 |
= stoma (strict sense) |
FEATURE |
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The opening between and regulated by the two guard cells of a stomate (stomatal apparatus). |
stomatal pore 2 |
= stomium |
FEATURE |
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The opening in the wall of a sporangium, between the lip cells, through which the spores exit; in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. |
stomium pl. stomia |
= stomatal pore |
FEATURE |
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The opening in the wall of a sporangium, between the lip cells, through which the spores exit; in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. |
seed coat |
= testa |
STRUCTURE |
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The outer protective layer of a seed, developed from the ovular integument(s). |
testa pl. testae |
= seed coat |
STRUCTURE |
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The outer protective layer of a seed, developed from the ovular integument(s). |
bark |
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STRUCTURE |
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The outermost portion of any shoot or root axis having secondary growth, consisting of all those tissues outside the vascular cambium; sometimes exhibiting zonation into inner, living bark and outer, dead bark; usually described only as to external appearance. |
epicarp |
= exocarp |
STRUCTURE |
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The outermost tissue layer of a pericarp. |
exocarp |
= epicarp |
STRUCTURE |
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The outermost tissue layer of a pericarp. |
replum pl. repla |
< dissepiment, septum |
STRUCTURE |
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The persistent wall or partition that separates the two locules of a silicle or silique. |
gynoecium pl. gynoecia var. gynaecium |
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STRUCTURE |
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The pistil(s) of a single flower together with any ontogenetically equivalent or subordinate structures present, taken collectively; the total female (ovule-producing) structural complement of a single flower. It may include one to many pistils, each simple or compound. |
casing |
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STRUCTURE |
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The portion (if any) of a floral tube that is adnate to the gynoecium. See also collar, neck. |
pericarp |
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STRUCTURE |
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The portion of a fruit wall that is derived from the ovary wall; consisting of three more or less distinct tissue layers (exocarp or epicarp, mesocarp, and endocarp) that may or may not differ greatly in structure and/or function; the wall of a fruit, excluding any tissues of extra-ovarian (accessory) origin. |
limb 2 |
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STRUCTURE |
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The portion of the corolla of a bisexual or staminate disc floret distal to the level of filament insertion; in Asteraceae (Compositae). |
corolla tube 2 |
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STRUCTURE |
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The portion of the corolla of a bisexual or staminate disc floret proximal to the level of filament insertion; in Asteraceae (Compositae). |
radicle |
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STRUCTURE |
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The primary root, or its primordium, in an embryo; the portion of an embryo axis that develops into the root. |
germination 1 |
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CHARACTER |
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The process wherein a dormant embryo resumes active metabolism and growth, the primary root and shoot emerging from the seed coat, the young sporophyte thereupon entering the seedling stage. |
germination 2 |
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CHARACTER |
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The process wherein the contents of a spore begin active growth, exiting the confines of the spore wall via a pore or crack and giving rise to a gametophyte. |
lemma pl. lemmata, lemmas |
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STRUCTURE |
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The proximal bract of the (usually) two that immediately subtend the flower in a grass (Poaceae) floret; the other is the palea. |
hypochilium |
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STRUCTURE |
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The proximal portion of a labellum (lip) that has distinct proximal, distal, and sometimes also central parts; in Orchidaceae. See also epichilium, mesochilium. |
ovary |
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STRUCTURE |
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The proximal portion of a pistil (either simple or compound) within which the ovules are borne; usually of somewhat greater diameter and/or volume than the remainder of the pistil. |