Glossary of Plant Anatomy

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palea [PO:0009038; plant anatomy term ]
A flower bract (PO:0009034) that is the upper/distal of the two bracts (PO:0009055) enclosing a (PO:0009082) spikelet floret.
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palea awn [PO:0025350; plant anatomy term ]
An awn that is part of a palea.
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paleal apiculus [PO:0006033; plant anatomy term ]
A short, abrupt, flexible point present at the apex of the palea.
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palisade mesophyll [PO:0005648; plant anatomy term ]
Parenchyma containing closely packed elongated chlorenchymatous cells oriented perpendicular to the leaf surface and which are active in photosynthesis.
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palisade mesophyll cell [PO:0006206; plant anatomy term ]
Elongated chlorenchymatous cell oriented perpendicular to the leaf surface and which is active in photosynthesis.
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palisade mesophyll intercellular space [PO:0025397; plant anatomy term ]
A leaf mesophyll intercellular space that is part of a palisade mesophyll.
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palmate leaf [PO:0020046; plant anatomy term ]
A once-compound leaf divided into several leaflets which arise at the same point, there being no rachis.
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papilla cell [PO:0025166; plant anatomy term ]
An epidermal pavement cell with a short protuberance.
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pappus [PO:0025393; plant anatomy term ]
A collective organ part structure that has a parts one or more pappus elements (scales, awns, or bristles) at the apex of an inferior ovary just beneath or outside the corolla.
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pappus element [PO:0025394; plant anatomy term ]
A cardinal organ part that is a segment of a pappus.
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paraclade cortex [PO:0004721; plant anatomy term ]
A portion of cortex (PO:0005708) that is part of an inflorescence branch (PO:0009081), also called a paraclade.
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paraphyllium [PO:0030069; plant anatomy term ]
A portion of epidermal tissue that is an outgrowth from the epidermis between the leaves of a gametophore axis.
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paraphysis [PO:0030070; plant anatomy term ]
A slender, usually uniseriate multicellular trichome (PO:0025162) that grows intermixed with the gametangia.
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parenchyma [PO:0005421; plant anatomy term ]
A portion of ground tissue (PO:0025059) composed of polyhedral cells typically with thin, non-lignified cellulosic cell walls and nucleate, living protoplasts.
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parenchyma cell [PO:0000074; plant anatomy term ]
A relatively unspecialized ground tissue cell with a nucleate protoplast.
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parenchyma sheath [PO:0006024; plant anatomy term ]
A single layered, parenchymatous bundle sheath characterized by presence of large quantity of starch.
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passage cell [PO:0000353; plant anatomy term ]
A ground tissue cell that is part of an exodermis or an endodermis and remains thin walled when the associated cells develop thick secondary walls.
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pedicel cortex [PO:0004722; plant anatomy term ]
A portion of cortex (PO:0005708) that is part of a pedicel (PO:0009052).
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pedicel of ear spikelet [PO:0006415; plant anatomy term ]
This is the ultimate branch of the pedicellate ear spikelet.
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pedicel of tassel spikelet [PO:0006416; plant anatomy term ]
This is the ultimate branch of the pedicellate tassel spikelet.
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pedicel vascular system [PO:0005012; plant anatomy term ]
A shoot axis vascular system that includes the totality of the portions of vascular tissue in their specific arrangement in a pedicel.
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peduncle [PO:0009053; plant anatomy term ]
A shoot axis that extends from the last foliage leaf on a stem or branch until the next distal node.
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peduncle epidermis [PO:0025152; plant anatomy term ]
A portion of branch epidermis that is part of a peduncle.
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peduncle trichome [PO:0025153; plant anatomy term ]
A shoot axis trichome that is part of a peduncle epidermis.
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pentarch protoxylem [PO:0025562; plant anatomy term ]
A portion of root exarch protoxylem (PO:0025555) tissue in which the primary xylem (PO:0005849) of the root system (PO:0025025) has five protoxylem strands or poles, and differentiation progresses centripetally, with the oldest elements (protoxylem) farthest from the center of the plant axis (PO:0025004).
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perianth [PO:0009058; plant anatomy term ]
A collective phyllome structure (PO:0025023) that includes as parts the corolla (PO:0009059) and/or the calyx (PO:0009060); or one or more tepals (PO:0009033).
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periblem [PO:0008036; plant anatomy term ]
A portion of meristem tissue that forms the cortex.
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pericarp [PO:0009084; plant anatomy term ]
A portion of plant tissue (PO:0009007) that is the outer layer (wall) of a fruit (PO:0009001), and develops from a plant ovary (PO:0009072) or a carpel (PO:0009030) wall.
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pericarp vascular bundle [PO:0025203; plant anatomy term ]
A vascular bundle (PO:0005020) that is part of a pericarp (PO:0009084).
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perichaetal bract [PO:0030030; plant anatomy term ]
A bract (PO:0009055) that subtends an archegonium (PO:0025126).
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pericycle [PO:0006203; plant anatomy term ]
A portion of ground tissue that is part of a root stele located between the phloem and endodermis.
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pericycle cell [PO:0025261; plant anatomy term ]
A ground tissue cell that is part of a portion of pericycle.
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pericyclic lateral root [PO:0025494; plant anatomy term ]
A lateral root (PO:0025495) that develops from a pericyclic lateral root primordium (PO:0025492).
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pericyclic lateral root primordium [PO:0025492; plant anatomy term ]
A lateral root primordium (PO:0000016) that develops from a portion of pericycle tissue (PO:0006203) and is committed to the development of a pericyclic lateral root (PO:0025494).
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periderm [PO:0005046; plant anatomy term ]
A peripheral portion of ground tissue in a plant axis that is composed of phellogen, phellem, and phelloderm.
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perigonial bract [PO:0030028; plant anatomy term ]
A bract (PO:0009055) that subtends an antheridium (PO:0025125).
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perigynium [PO:0009044; plant anatomy term ]
Sac-like bract subtending the pistillate flower, as in Carex.
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perimedullary zone [PO:0025058; plant anatomy term ]
A portion of parenchyma (PO:0005421) that is the outer layer of the pith (PO:0006109).
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peripheral zone [PO:0000225; plant anatomy term ]
A portion of meristem tissue (PO:0009013) which is the organogenic region of the meristem, characterized by higher rates of cell division.
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perisperm [PO:0020058; plant anatomy term ]
Diploid nutritive tissue in an angiosperm seed derived from nucellar tissue.
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peristome [PO:0030042; plant anatomy term ]
A single or double circle of peristome teeth inside a sporangium mouth.
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peristome tooth [PO:0030043; plant anatomy term ]
A cardinal organ part that is a single lobe of a peristome.
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persistent sepal [PO:0025245; plant anatomy term ]
A phyllome that develops from a sepal and remains attached to a fruit at maturity.
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persistent stamen [PO:0025247; plant anatomy term ]
A phyllome that develops from a stamen and remains attached to a fruit at maturity.
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persistent tepal [PO:0025246; plant anatomy term ]
A phyllome (PO:0006001) that develops from a tepal (PO:0009033) and remains attached to a fruit (PO:0009001) at maturity.
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petal [PO:0009032; plant anatomy term ]
A phyllome (PO:0006001) that is part of the corolla (PO:0009059), and is usually colored (not green).
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petal abaxial epidermis [PO:0006052; plant anatomy term ]
A portion of petal epidermis that covers the abaxial/lower surface of a petal.
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petal adaxial epidermis [PO:0006053; plant anatomy term ]
A portion of petal epidermis that covers the adaxial/upper surface of a petal.
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petal anlagen [PO:0025484; plant anatomy term ]
A phyllome anlagen (PO:0025430) that will give rise to a petal primordium (PO:0000021) and is part of a peripheral zone (PO:000225) of a flower meristem (PO:0000229).
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petal apex [PO:0025144; plant anatomy term ]
A phyllome apex (PO:0025139) that is part of a petal (PO:0009032).
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petal base [PO:0025146; plant anatomy term ]
A phyllome base (PO:0025140) that is part of a petal (PO:0009032).
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petal epidermis [PO:0006041; plant anatomy term ]
A portion of phyllome epidermis (PO:0025157) that is part of a petal (PO:0009032).
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petal margin [PO:0025008; plant anatomy term ]
A phyllome margin (PO:0025018) of a petal (PO:0009032).
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petal mesophyll [PO:0006071; plant anatomy term ]
The chloroplast-containing, photosynthetic parenchymatous tissue situated between the two epidermal layers of the petal.
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petal parenchyma [PO:0006069; plant anatomy term ]
A portion of parenchyma (PO:0005421) tissue that is part of a petal (PO:0009032).
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petal primordium [PO:0000021; plant anatomy term ]
A phyllome primordium (PO:0025128) that develops from a petal anlagen (PO:0025484) and is committed to the development of a petal (PO:0009032).
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petal spur [PO:0025511; plant anatomy term ]
A cardinal organ part (PO:0025001) that is a slender, hollow extension of a petal (PO:0009032).
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petal stomatal complex [PO:0025218; plant anatomy term ]
A phyllome stomatal complex (PO:0025215) that is part of a petal (PO:0009032).
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petal tip [PO:0025149; plant anatomy term ]
A phyllome tip that is part of a petal apex.
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petal trichome [PO:0025187; plant anatomy term ]
A phyllome trichome that is part of a petal epidermis.
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petal vascular system [PO:0000054; plant anatomy term ]
A phyllome vascular system (PO:0025206) that includes the totality of the portions of vascular tissue in their specific arrangement in a petal (PO:0025218).
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petiole [PO:0020038; plant anatomy term ]
A stalk of a leaf.
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petiole abaxial epidermis [PO:0008029; plant anatomy term ]
A portion of petiole epidermis that covers the abaxial/lower surface of a petiole.
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petiole adaxial epidermis [PO:0008027; plant anatomy term ]
A portion of petiole epidermis that covers the adaxial/upper surface of a petiole.
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petiole canal [PO:0025133; plant anatomy term ]
A canal that is part of a petiole.
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petiole cortex [PO:0000053; plant anatomy term ]
A portion of cortex (PO:0005708) that is part of a petiole (PO:0020038).
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petiole distal end [PO:0008026; plant anatomy term ]
The region of the petiole distal to its stem attachment site or proximal to the leaf lamina.
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petiole epidermis [PO:0000051; plant anatomy term ]
A portion of leaf epidermis that is part of a petiole.
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petiole lamina [PO:0025129; plant anatomy term ]
A lamina (PO:0025060) that is part of a petiole (PO:0020038).
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petiole margin [PO:0025010; plant anatomy term ]
The margin of a flattened petiole.
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petiole parenchyma [PO:0006066; plant anatomy term ]
A portion of parenchyma tissue that is part of a petiole.
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petiole proximal end [PO:0008024; plant anatomy term ]
The region of the petiole proximal to its stem attachment site.
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petiole pulvinus [PO:0009111; plant anatomy term ]
Pulvinus of the petiole.
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petiole stomatal complex [PO:0025189; plant anatomy term ]
A leaf stomatal complex that is part of a petiole.
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petiole vascular bundle [PO:0025434; plant anatomy term ]
A vascular bundle (PO:0005020) that is part of a petiole vascular system (PO:0000052).
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petiole vascular system [PO:0000052; plant anatomy term ]
A vascular system that includes the totality of the portions of vascular tissue in their specific arrangement in a leaf petiole.
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petiolule [PO:0020050; plant anatomy term ]
A stalk of a leaflet.
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phellem [PO:0004003; plant anatomy term ]
A portion of ground issue centrifugally derived from cork cambium, non-living at maturity, and having suberized walls.
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phelloderm [PO:0005050; plant anatomy term ]
A portion of ground tissue often resembling cortical parenchyma produced centripetally by the cork cambium.
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phloem [PO:0005417; plant anatomy term ]
A portion of vascular tissue (PO:0009015) that has as parts sieve elements (PO:0025406).
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phloem fiber cell [PO:0004519; plant anatomy term ]
A fiber cell (PO:0025407) that is part of a portion of phloem (PO:0005417) tissue.
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phloem mother cell [PO:0000400; plant anatomy term ]
A cambial initial cell (PO:0000295) which is destined to differentiate into secondary phloem.
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phloem pole pericycle cell [PO:0000065; plant anatomy term ]
A pericycle cell that is adjacent to the protophloem of a vascular bundle.
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phloem sap [PO:0025540; plant anatomy term ]
A plant sap (PO:0025538) that is an aqueous solution which may contain sugars, mineral elements, and plant hormones, and is transported through the phloem sieve elements (PO:0025406).
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phyllode leaf [PO:0025335; plant anatomy term ]
An adult ensiform leaf with a lamina that develops in a median plane, rather a transverse plane, throughout the length of the leaf and is a result of increased activity of the adaxial meristem early in development.
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phyllome [PO:0006001; plant anatomy term ]
A lateral plant organ (PO:0009008) produced by a shoot apical meristem (PO:0020148).
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phyllome abaxial meristem [PO:0025402; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that is found on the abaxial side of a developing phyllome (PO:0006001).
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phyllome adaxial meristem [PO:0025400; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that is found on the adaxial side of a developing phyllome (PO:0006001).
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phyllome anlagen [PO:0025430; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that is part of a peripheral zone (PO:0000225) of a shoot apical meristem (PO:0020148) and will give rise to a phyllome primordium (PO:0025128).
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phyllome apex [PO:0025139; plant anatomy term ]
The apical portion of a phyllome.
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phyllome base [PO:0025140; plant anatomy term ]
The basal part of a phyllome (PO:0006001), where it attaches to a shoot axis (PO:0025029).
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phyllome epidermis [PO:0025157; plant anatomy term ]
A portion of shoot epidermis (PO:0006035) that is part of a phyllome (PO:0006001).
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phyllome founder cell [PO:0025586; plant anatomy term ]
A native plant cell (PO:0025606) that is part of the phyllome anlagen (PO:0025430).
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phyllome guard cell [PO:0025236; plant anatomy term ]
A guard cell that is part of a phyllome stomatal complex.
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phyllome lamina [PO:0025396; plant anatomy term ]
An organ lamina (PO:0025513) that is part of a phyllome (PO:0006001).
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phyllome lamina areole [PO:0025391; plant anatomy term ]
A cardinal organ part (PO:0025001) that is part of a phyllome lamina (PO:0025396) and is completely surrounded by phyllome lamina veins (PO:0025348) and cannot be divided into any smaller parts that are completely surrounded by phyllome lamina veins.
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phyllome lamina crena [PO:0025516; plant anatomy term ]
A cardinal organ part (PO:0025001) that is a rounded projection on a phyllome margin (PO:0025018) for which the corresponding phyllome sinus (PO:0025383) extends less than one quarter of the distance to the center of the long axis of the phyllome lamina (PO:0025396).
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phyllome lamina lobe [PO:0025514; plant anatomy term ]
A cardinal organ part (PO:0025001) that is a projection on a phyllome margin (PO:0025018) for which the corresponding phyllome sinus (PO:0025383) extends one quarter or more of the distance to the center of the long axis of the phyllome lamina (PO:0025396).
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phyllome lamina tooth [PO:0025515; plant anatomy term ]
A cardinal organ part (PO:0025001) that is an angular projection on a phyllome margin (PO:0025018) for which the corresponding phyllome sinus (PO:0025383) extends less than one quarter of the distance to the center of the long axis of the phyllome lamina (PO:0025396).
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phyllome lamina vein [PO:0025348; plant anatomy term ]
A vascular bundle (PO:0005020) that is part of a phyllome lamina (PO:0025396).
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phyllome margin [PO:0025018; plant anatomy term ]
An organ margin (PO:0025005) that is part of a phyllome (PO:0006001).
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phyllome marginal meristem [PO:0025404; plant anatomy term ]
A portion of meristem (PO:0009013) tissue that is part of a phyllome margin (PO:0025018) of an expanding phyllome (PO:0006001) and has as parts marginal and submarginal initials.
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phyllome plate meristem [PO:0025428; plant anatomy term ]
A portion of meristem (PO:0009013) tissue in which the planes of cell division in each layer are anticlinal to the surface of the phyllome (PO:0006001).
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phyllome primordium [PO:0025128; plant anatomy term ]
A primordium (PO:0025127) that develops from a phyllome anlagen (PO:0025430) and is part of a shoot apex (PO:0000037) and is committed to the development of a phyllome (PO:0006001).
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phyllome sinus [PO:0025383; plant anatomy term ]
A plant anatomical space that is a phyllome marginal embayment, incision or indentation between marginal projections of any sort, typically lobes, teeth, or the base of cordate phyllomes.
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phyllome stomatal complex [PO:0025215; plant anatomy term ]
A stomatal complex (PO:0002000) that is part of a phyllome (PO:0006001).
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phyllome stomatal pore [PO:0025234; plant anatomy term ]
A stomatal pore that is part of a phyllome stomatal complex.
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phyllome substomatal cavity [PO:0025398; plant anatomy term ]
A substomatal cavity that is part of a phyllome.
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phyllome tip [PO:0025141; plant anatomy term ]
The apical most portion of a phyllome apex.
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phyllome trichome [PO:0025186; plant anatomy term ]
A trichome that is part of a phyllome epidermis.
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phyllome vascular system [PO:0025206; plant anatomy term ]
A vascular system that includes the totality of the portions of vascular tissue in their specific arrangement in a phyllome.
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pinnate leaf [PO:0020045; plant anatomy term ]
A once-compound leaf with leaflets borne along a rachis.
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pistillate flower [PO:0025599; plant anatomy term ]
A flower (PO:0009046) that includes as part a single carpel (PO:0009030) or a gynoecium (PO:0009062), but the androecium (PO:0009061) is absent or has aborted during development.
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pistillate inflorescence [PO:0025598; plant anatomy term ]
An inflorescence (PO:0009049) that includes as part only pistillate flowers (PO:0025599).
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pistillode [PO:0009078; plant anatomy term ]
A sterile pistil, often rudimentary.
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pith [PO:0006109; plant anatomy term ]
A maximal portion of parenchyma (PO:0005421) in the center of a shoot axis (PO:0025029) or root (PO:0009005).
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placenta [PO:0025078; plant anatomy term ]
A portion of plant tissue at the interface between two plant structures, one of which is in a gametophyte development stage (PO:id) and one of which is in a sporophyte development stage (PO:id), and that has as parts transfer cells (PO:0000078).
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placentoid [PO:0020005; plant anatomy term ]
A portion of parenchyma tissue that is part of a connective and projects into a pollen sac.
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plant anatomical entity [PO:0025131; plant anatomy term ]
An anatomical entity that is or was part of a plant.
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plant anatomical space [PO:0025117; plant anatomy term ]
An anatomical space that is part of a plant.
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plant axis [PO:0025004; plant anatomy term ]
An axial plant organ (PO:0009008).
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plant axis differentiation zone [PO:0025119; plant anatomy term ]
A cardinal organ part that is part of a plant axis and is located behind the elongation zone and contains cells that are differentiating into their final form and function.
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plant axis elongation zone [PO:0025180; plant anatomy term ]
A cardinal organ part that is part of a plant axis that is located directly behind an apical meristem, in which the cells are undergoing longitudinal expansion.
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plant callus [PO:0005052; plant anatomy term ]
A portion of plant tissue (PO:0009007) that consists of mass of undifferentiated plant cells (PO:0009002).
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plant cell [PO:0009002; plant anatomy term ]
A cell which is a plant structure (PO:0009011).
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plant cuticle [PO:0000022; plant anatomy term ]
A portion of plant substance (PO:0025161) composed of cutin (PO:0025385), a polyester matrix of hydroxy- and hydroxy epoxy fatty acids C16 and C18 chains, embedded and overlayed with cuticular wax (PO:0025386) and forming a layer on the surface of a plant epidermis (PO:0005679).
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plant cuticle proper [PO:0025387; plant anatomy term ]
A portion of plant substance (PO:0025161) that is the inner layer of a plant cuticle (PO:0000022), composed primarily of cutin (PO:0025385), embedded and overlayed with cuticular wax (PO:0025386).
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plant cuticle ridge [PO:0025536; plant anatomy term ]
A portion of plant cuticle (PO:000022) that forms a ridge, may be overlayed with epicuticular wax (PO:0025388).
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plant egg cell [PO:0020094; plant anatomy term ]
A gamete (PO:0025006) produced by an archegonium (PO:0025126) or an embryo sac (PO:0025074).
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plant embryo [PO:0009009; plant anatomy term ]
A whole plant (PO:0000003) that participates in the plant embryo stage (PO:0007631).
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plant embryo axis [PO:0019018; plant anatomy term ]
A plant axis (PO:0025004) that is the axial part of a plant embryo (PO:0009009).
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plant embryo coleoptile [PO:0025286; plant anatomy term ]
A coleoptile (PO:0020033) that is part of a plant embryo (PO:0009009).
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plant embryo cotyledon [PO:0025470; plant anatomy term ]
A cotyledon (PO:0020030) that is part of a plant embryo (PO:0009009).
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plant embryo proper [PO:0000001; plant anatomy term ]
An embryonic plant structure (PO:0025099) that is the body of a developing plant embryo (PO:0009009) attached to the maternal tissue in an plant ovule (PO:0020003) by a suspensor (PO:0020108).
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plant embryo radicle [PO:0025296; plant anatomy term ]
A radicle (PO:0020031) that is part of a plant embryo (PO:0009009).
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plant fiber cell [PO:0025407; plant anatomy term ]
A sclerenchyma cell (PO:0000077) that is elongated and tapering.
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plant organ [PO:0009008; plant anatomy term ]
A multi-tissue plant structure (PO:0025496) that is a functional unit, is a proper part of a whole plant (PO:0000003), and includes portions of plant tissue (PO:0009007) of at least two different types that derive from a common developmental path.
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plant ovary [PO:0009072; plant anatomy term ]
A plant structure (PO:0009011) that is the basal portion of a carpel (PO:0009030) or group of fused carpels and encloses the plant ovule(s) (PO:0020003).
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plant ovary ovule [PO:0025490; plant anatomy term ]
A plant ovule (PO:0020006) that is part of a plant ovary (PO:0009072).
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plant ovule [PO:0020003; plant anatomy term ]
A plant organ (PO:0009008) that has as parts a nucellus (PO:0020020) in which a female gametophyte (PO:0025279) is located, one or two integuments (PO:0020021), and a funicle (PO:0020006).
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plant protoplast [PO:0000006; plant anatomy term ]
A cultured plant cell from which the entire plant cell wall has been removed.
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plant resin [PO:0025603; plant anatomy term ]
A portion of plant substance (PO:0025161) that consists of a complex mixture of organic aromatic compounds such as mono-, sesqui-, and diterpenoids.
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plant sap [PO:0025538; plant anatomy term ]
A portion of plant substance (PO:0025161) that is an aqueous solution that can be transported through the apoplast (GO:0048046) or symplast (GO:0055044).
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plant sperm cell [PO:0000084; plant anatomy term ]
A gamete (PO:0025006) produced by an antheridium (PO:0025125) or a microgametophyte (PO:0025280).
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plant spore [PO:0025017; plant anatomy term ]
A whole plant (PO:0000003) that arises through meiosis and is contained in a spore wall.
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plant structure [PO:0009011; plant anatomy term ]
An anatomical structure that is or was part of a plant, or was derived from a part of a plant.
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plant zygote [PO:0000423; plant anatomy term ]
A native plant cell (PO:0025606) which is a whole plant (PO:0000003) in the plant zygote stage (PO:0001097).
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plerome [PO:0008035; plant anatomy term ]
A meristem forming the core of the axis composed of the primary vascular tissues and associated ground tissue, such as pith and interfascicular regions.
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plumule [PO:0020032; plant anatomy term ]
The shoot apex (PO:0000037) of the plant embryo (PO:0009009), above the cotyledonary node (PO:0025321).
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pneumatophore [PO:0025357; plant anatomy term ]
A lateral root that is erect and protrudes above the soil or water.
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pneumatorhiza [PO:0025358; plant anatomy term ]
A small lateral root that grows from a prop root and has a mealy surface texture.
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pollen [PO:0025281; plant anatomy term ]
A microgametophyte (PO:0025280) that develops from a microspore (PO:0020048) is located in a pollen sac (PO:0025277).
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pollen sac [PO:0025277; plant anatomy term ]
A microsporangium that is part of a sporophyll and where the pollen grains develop and are located after they develop.
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pollen sperm cell [PO:0025121; plant anatomy term ]
A plant sperm cell (PO:0000084) that is part of the pollen (PO:0025281).
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pollen tube cell [PO:0025195; plant anatomy term ]
A native plant cell (PO:0025606) that develops from a microgametophyte vegetative cell (PO:0020099) and forms a tubular extension of the pollen (PO:0025281).
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polyarch protoxylem [PO:0025563; plant anatomy term ]
A portion of root exarch protoxylem (PO:0025555) tissue in which the primary xylem (PO:0005849) of the root system (PO:0025025) has more than five protoxylem strands or poles, and differentiation progresses centripetally, with the oldest elements (protoxylem) farthest from the center of the plant axis (PO:0025004).
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portion of embryo plant tissue [PO:0025233; plant anatomy term ]
A portion of plant tissue that is part of a plant embryo.
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portion of ground tissue [PO:0025059; plant anatomy term ]
Any portion of plant tissue (PO:0009007) other than epidermis (PO:0005679) or vascular tissue (PO:0009015).
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portion of meristem tissue [PO:0009013; plant anatomy term ]
A portion of plant tissue (PO:0009007) in which plant cells (PO:0009002) have retained their embryonic characteristics, or have reverted to them secondarily, and that divide to produce new cells that can undergo differentiation to form mature tissues, i.e. they have a capacity for morphogenesis and growth.
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portion of plant substance [PO:0025161; plant anatomy term ]
A portion of organism substance that is or was part of a plant.
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portion of plant tissue [PO:0009007; plant anatomy term ]
A plant structure (PO:0009011) that consists predominantly of similarly specialized plant cells (PO:0009002) of one or more types.
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portion of secretory tissue [PO:0005656; plant anatomy term ]
Tissues that form specialized structures producing a secretion.
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portion of transfusion tissue [PO:0006084; plant anatomy term ]
Tissue consisting of tracheids and parenchyma cells, associated with the vascular bundle.
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portion of transmitting tissue [PO:0020102; plant anatomy term ]
A portion of ground tissue in the style of a carpel through which a pollen tube grows; it connects a stigma and the inside of an ovary.
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portion of vascular tissue [PO:0009015; plant anatomy term ]
A portion of plant tissue (PO:0009007) that has as part one or more tracheary elements (PO:0000290) or sieve elements (PO:0025406).
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prickle [PO:0025169; plant anatomy term ]
A portion of epidermis that is a sclerified outgrowth.
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primary endosperm cell [PO:0000038; plant anatomy term ]
Cell produced by the fusion of sperm cell nucleus and two polar nuclei of the central cell (or diploid secondary endosperm nucleus, in cases where two polar nuclei fuse together before double fertilization). The first cell of the endosperm, often triploid.
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primary inflorescence branch [PO:0006321; plant anatomy term ]
An inflorescence branch (PO:0009081) arising from a first order inflorescence axis (PO:0025104).
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primary infructescence branch [PO:0025112; plant anatomy term ]
An infructescence branch (PO:0025243) arising from a first order infructescence axis (PO:0025244).
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primary leaf vein [PO:0025413; plant anatomy term ]
A leaf lamina vein (PO:0020138) that connects directly to a petiole vascular system (PO:0000052) or a shoot axis vascular system (PO:0000039).
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primary parietal cell [PO:0006010; plant anatomy term ]
A native plant cell (PO:0025606) which is formed by the division of a male archesporial cell (PO:0006014), and is part of the anther wall primary parietal cell layer (PO:0006006).
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primary phloem [PO:0006075; plant anatomy term ]
A portion of phloem (PO:0005417) tissue that develops from the procambium (PO:0025275).
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primary phloem sieve cell [PO:0025454; plant anatomy term ]
A sieve cell (PO:0025415) that is part of a portion of primary phloem (PO:0006075).
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primary phloem sieve element [PO:0025452; plant anatomy term ]
A sieve element (PO:0025406) that is part of a portion of primary phloem (PO:0006075).
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primary phloem sieve tube element [PO:0025455; plant anatomy term ]
A sieve tube element (PO:0000289) that is part of a portion of primary phloem (PO:0006075).
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primary root [PO:0020127; plant anatomy term ]
A root (PO:0009005) that develops directly from an seedling radicle (PO:0020127).
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primary root apical meristem [PO:0006081; plant anatomy term ]
A root apical meristem (PO:0020147) that gives rise to a primary root (PO:0020127).
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primary root differentiation zone [PO:0003015; plant anatomy term ]
A root differentiation zone that is part of a primary root.
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primary root elongation zone [PO:0025257; plant anatomy term ]
A root elongation zone that is part of a primary root tip.
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primary root tip [PO:0000026; plant anatomy term ]
The portion of the primary root including the meristem and root cap.
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primary shoot system [PO:0006341; plant anatomy term ]
A shoot system (PO:0009006) that develops from an embryo shoot apical meristem (PO:0006362).
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primary sporogenous cell [PO:0006088; plant anatomy term ]
A native plant cell (PO:0025606) is formed by the division of the male archesporial initial. After several mitotic divisions these cells differentiate into pollen mother cells.
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primary thickening meristem [PO:0005039; plant anatomy term ]
A shoot lateral meristem (PO:0006344) that is part of a shoot axis (PO:0025029) and has a parts multiple layers of meristematic cells (PO:0004010) located near the shoot apical meristem (PO:0020148).
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primary vascular tissue [PO:0025408; plant anatomy term ]
A portion of vascular tissue (PO:0009015) that develops from a procambium (PO:0025275).
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primary xylem [PO:0005849; plant anatomy term ]
A portion of xylem (PO:0005352) tissue that develops from the procambium (PO:0025275).
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primary xylem tracheary element [PO:0025444; plant anatomy term ]
A tracheary element (PO:0000290) that is part of a primary xylem tissue (PO:0005849).
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primary xylem tracheid [PO:0025446; plant anatomy term ]
A tracheid (PO:0000301) that is part of a xylem tissue (PO:0005849).
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primary xylem vessel [PO:0025450; plant anatomy term ]
A xylem vessel (PO:0025417) that is part of a primary xylem tissue (PO:0005849).
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primary xylem vessel member [PO:0025448; plant anatomy term ]
A xylem vessel member (PO:0002003) that is part of a primary xylem tissue (PO:0005849).
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primordium [PO:0025127; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that has as parts protoderm (PO:0006210) and sub-epidermal meristematic tissue and is committed to the development of a particular plant structure (PO:0009011).
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procambial cell [PO:0025258; plant anatomy term ]
A meristematic cell (PO:0004010) that is part of a portion of procambium (PO:0025275).
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procambium [PO:0025275; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that undergoes differentiation to form the primary vascular tissue (PO:0025408).
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procumbent ray secondary xylem parenchyma cell [PO:0004529; plant anatomy term ]
A ray secondary xylem parenchyma cell (PO:0004527) that is oriented with its longest dimension radial to the plant axis (PO:0025004) in which it is found.
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prop root [PO:0000044; plant anatomy term ]
A shoot-borne nodal root (PO:0003005) formed at a stem node above the ground, and growing directly into the soil.
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prophyll [PO:0009042; plant anatomy term ]
A phyllome that is the first organ or one of the first two organs formed at the base of an axillary shoot, often smaller and/or in a distinctively different position from leaves formed subsequently.
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prophyll margin [PO:0025013; plant anatomy term ]
The margin of a prophyll.
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prophyll tendril [PO:0025367; plant anatomy term ]
A prophyll that is slender and coiling and lacks a lamina.
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protective layer [PO:0006212; plant anatomy term ]
A portion of plant tissue (PO:0009007) composed of a layer of cells that is part of the abscission zone (PO:0000146) that have lignin and suberin depositions and are found on the axial side of the break or exposed surface of abscission.
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proteoid root [PO:0000067; plant anatomy term ]
A root (PO:0009005) that forms one or more clusters of closely spaced lateral roots (PO:0020121) of limited growth along its length.
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prothallial cell [PO:0025533; plant anatomy term ]
A native plant cell (PO:0025606) which is vegetative and develops from the division of the microspore (PO:0020048) of vascular plants other than angiosperms.
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protoderm [PO:0006210; plant anatomy term ]
A portion of meristem tissue (PO:0009013) that is the outer layer of an apical meristem (PO:0020144), or the outer layer of a plant embryo proper (PO:0000001), and gives rise to a portion of epidermis (PO:0005679).
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protonema [PO:0030003; plant anatomy term ]
A portion of chlorenchyma tissue that develops directly from a spore and grows by division of an apical cell to form filaments that are one cell wide and dichotomously branching.
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protonema meristematic apical cell [PO:0030046; plant anatomy term ]
A gametophyte meristematic apical cell that is part of a protonema.
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protonema side branch initial cell [PO:0030067; plant anatomy term ]
An protonema sub-apical initial that gives rise to a branch of a protonema.
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protonema sub-apical initial cell [PO:0030086; plant anatomy term ]
An initial cell that is produced by longitudinal division of a sub-apical cell of a protonema.
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protonemal rhizoid [PO:0030079; plant anatomy term ]
A rhizoid that is part of a protonema and develops from a protonemal side branch rhizoid initial.
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protonemal side branch rhizoid initial cell [PO:0030077; plant anatomy term ]
A protonema side branch initial that gives rise to a protonemal rhizoid.
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protophloem [PO:0006077; plant anatomy term ]
A portion of primary phloem (PO:0006075) tissue has as parts the first-formed sieve elements (PO:0025406) at a particular location and does not have companion cells (PO:0000071, in angiosperms) or albuminous cells (PO:0025412, in gymnosperms) associated with the sieve elements.
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protosporangium endothecium [PO:0030085; plant anatomy term ]
A portion of ground tissue that is the tissue internal to an amphithecium early in sporangium development.
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protoxylem [PO:0000272; plant anatomy term ]
A portion of primary xylem (PO:0000272) tissue that has as part one or more protoxylem tracheary elements (PO:0025575) embedded in parenchyma (PO:0005421) tissue.
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protoxylem tracheary element [PO:0025575; plant anatomy term ]
A primary xylem tracheary element (PO:0025444) with predominately annular or helical secondary wall thickening that are the first formed tracheary elements (PO:0000290) at a particular location.
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pseudopodium [PO:0030055; plant anatomy term ]
A gametophore axis that is a leafless extension of a gametophore stem or branch on which a sporophyte is borne.
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pseudostem [PO:0025248; plant anatomy term ]
A collective organ part structure that forms a cylindrical false stem composed concentric leaf sheaths.
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pulvinus [PO:0009000; plant anatomy term ]
A cardinal organ part (PO:0025001) at the apex or base of a petiole, petiolule, leaf sheath, or branch that is differentiated from the remaining organ parts by its enlarged cross section.
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