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Perigynous ovary
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Referring to a flower in which the sepals, petals, and stamens arise from the rim of a cuplike hypanthium surrounding the ovary. |
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Peripheral filaments
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Protein filaments associated with sieve-element plastids. |
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Personate
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Referring to a bilabiate corolla with an expansion on the lower lip that blocks entry into the tube; e.g., in some species of Acanthaceae. |
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Petal
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An outermost segment of the corolla. |
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Petal lobe
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A lobe of the corolla that arises from the corolla tube. |
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Pistil
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The female part of the flower composed of the ovary, style, and stigma. |
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Pistillate flower
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Referring to unisexual flowers with functional gynoecia but without functional stamens (staminodes may be present). Same as female flower. |
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Pistillode
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A rudimentary, sterile gynoecia. |
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Placenta (plural = placentae)
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The structure in the ovary to which the ovules are attached. |
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Placental obturator
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A massive outgrowth of the placenta. In the Styracaceae, the micropyle of each ovule opens upon an obturator; the obturators may or may not be connate. |
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Placentation
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In broadest terms, the arrangement of ovules within the ovary. See axile, basal, free-central, and parietal placentation. |
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Placentation basal
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A type of placentation in which the ovule is attached to the floor of the locule. |
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Placentation free-central
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A type of placentation in which the ovules are borne on a central column arising from the base of a unilocular ovary. |
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Polar nuclei
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Two nuclei that migrate to the center of the embryo sac and fuse with a male nucleus (sperm) to form the primary endosperm nucleus which divides and sometimes forms the endosperm. |
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Pollen
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Male reproductive structures contained within the anther of the stamen and usually released at anthesis. Same as microgametophytes. |
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Pollinarium (plural = pollinaria)
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The pollen-bearing structure of Orchidaceae composed of a viscidium, a stipe, and pollinia. |
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Pollinium (plural = pollinia)
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An aggregate pollen mass characteristic of Orchidaceae and those of Apocynaceae subfamily Asclepiadoideae. |
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Polyandrous
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Referring to an androecium with numerous stamens. Same as polystemonous. |
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Polypetalous corolla
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Having petals free from one another. Same as choripetalous; opposite of sympetalous. |
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Polystemonous
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Having many stamens. Same as polyandrous. |
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Polysymmetric flower
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A flower, capable of being divided, by more than one line passing through the middle of the flower, into two equal parts that are mirror images of one another; e.g., in Gustavia (Lecythidaceae), species of Myrtaceae, and species of Rubiaceae. Same as acinomorphic, radially symmetrical, and regular flowers and opposite of zygomorphic, monosymmetric, bilateral, and irregular flowers. This term can refer to other plant parts as well. |
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Poricidal anther dehiscence
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Referring to anthers that shed their pollen via terminal apertures; e.g., Gustavia spp. (Lecythidaceae) and Solanum spp. (Solanaceae). |
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Pseudanthium (plural = pseudanthia)
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A false flower; e.g., the inflorescence of species of Asteraceae and Dalechampia (Euphorbiaceae). |
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Pseudodisc
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In some Menispermaceae, the button-shaped fleshy whorl of petals. |
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Pseudostaminodia (singular = pseudostaminodium)
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In the Amaranthaceae, referring to sterile, filamentous, entire to fimbriate processes as long as or longer than the stamens and alternating with them. |
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