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Egg
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The female reproductive part of a plant. In the flowering plants (angiosperms), the egg is located at the micropylar end of the megagameophyte flanked on each side by a synergid cell. After fertilization the ege develops into the embryo and the embryo develops into the adult plant. |
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Elaiosome
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A fleshy, oily outgrowth of the seed coat that often attracts ants for dispersing the seeds. Compare with aril and sarcotesta. |
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Elaiosome
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A fleshy, oily outgrowth of the seed coat that is eaten by ants. In the process, the ants often disperse the seeds away from the mother plant. |
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Electronic key
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An electronic key takes advantage of a database to facilitate the identification of an unknown plant to family, genus, or species. Electronic keys generally consist of four boxes as follows: (1) characters and character states upper left hand box), (2) taxa included in the keys, e.g., all of the genera, species, and infraspecific taxa in a plant family or all of the taxa in a Flora (upper right hand box). As choices are made species that do not have given characters are eliminated and appear in the lower right hand box, 3) all of the characters and character states that have been used while progressing through the key (lower left hand box), and 4) all of the taxa that have been rejected as a possible determination (lower right hand box). The advantages of electronic keys are 1) the key can entered no matter what characters are present in the plant being identified, 2) links can be made to electronic glossarys so the meaning of the characters can be understood by consulting their definations and seeing illustrations of them, 3) links can be made to family, generic, and species pages to confirm or reject determinatiions, and 4) a determination is always reached which ideally is a single taxon but if more than one taxon, the possibilities can be accepted or rejected based on viewing the taxon pages. |
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Elliptic
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Referring to the outline of essentially two-dimensional structures, such as leaves, bracts, petals, and sepals, which are widest at or near the middle. Elliptic shapes are divided based on their length/width ratios. An elliptic shape has a length to width ration from 2:1 to less than 3:1. |
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Emarginate
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Markedly notched, such as the apex of a leaf or other structure. |
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Embryo
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The young sporophytic plant found inside of the seed. |
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Embryo
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A young seed plant found within the seed, a dicotyledon embryo consists of the hypocotyle, cotyledons (usually two), and the epicotyl. |
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Embryo air chamber
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Referring to an embryo with a chamber inside of the seed caused by bowed cotyledons. |
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Embryo macropodial (= cotyledons absent)
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Massive embryo that shows no obvious cotyledons. Cotyledons absent is the preferred term. |
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Embryo sac
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The female gametophyte of angiosperms (flowering plants). Same as megagametophyte. |
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Emergent tree
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A species of tree in which adult individuals exceed the more or less continuous canopy layer of a forest. |
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Emergent tree layer
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A hypotherical layer in tropical forests made up of species of the tallest trees with crown emerging above the canopy tree layer. |
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Empheral
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A temperate zone plant that sends out leaves and photosynthesizes in the spring before the leaves of the trees appear. During this time the plant produces and stores enough carbohydrate to allow it to flower the following spring. Not long after flowering, the plant wilts and remains inconspicuous until the next spring. |
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Enclosed bud
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A bud that is either completed surrounded by the calyx or that has a pore-like or slit-like opening at early developmental stages. |
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Endemic
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Native to and restricted to a given geographic region or to a given soil type or other habitat. |
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Endocarp
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The innermost layer of the fruit wall. Compare with pericarp. |
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Endocarp buttress
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A raised, somewhat rounded ridge running the length of the endocarp in the fruits of species of Grias. |
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Endosperm
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The energy-rich food supply of the seed that is formed by the fusion of the sperm and polar nuclei of the female gametophyte, initially surrounds the embryo, and is often apparent in the seed; some seeds, however, do not have any apparent endosperm. |
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Endosperm
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The energy-rich food supply of the seed that is formed by the fusion of the sperm and polar nuclei of the female gametophyte, initially surrounds the embryo, and is often apparent in the seed; some seeds, however, do not have any apparent endosperm. |
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Entire
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Referring to a margin of a leaf, sepal, or petal that is not interrupted by teeth or lobes. |
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Eophyll
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The first true leaf of a seedling; i.e., the first leaf to appear after the cotyledon(s). |
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Eophyll
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The first leaves of a seedling, other than cotyledons, which may or may not be similar to adult leaves in form and position. |
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Ephemeral
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Lasting a short time; for example, a spring emphemeral in temperate regions that flowers and sets fruits before the canopy trees leaf out or a tree such as species of Tabebuia that flower for only a few days, thus the flowers are ephemeral. Same as evanescent. |
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Epicalyx
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A whorl of bracts on the pedicel, similar to sepals, and inserted below the calyx; most commonly found in species of Malvaceae.. |
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