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N

Naked: [Bud scales] {type} With no scales covering the immature shoot.

Nearly sessile: [Flowers, Leaflets, Leaves, Seed cones] {form of attachment} With a very short, somewhat indistinct stalk. (Compare with petiolate, petioulate, sessile and stalked.)

Nearly symmetric: [Seed cones] {symmetry} Not fully symmetric, but divisible into nearly equal halves along one or more planes.

Nectar: A sugary, sticky fluid secreted by many plants.

Nectary-bearing: [Petioles, Rachises] {special surface features} Bearing a glandular structure that secretes nectar [modified from W&K, p. 598 (see nectary)], often appearing as a protuberance, scale or pit.

Needle-like: [Leaves] {general form} With leaves that are more or less needle-shaped, and usually evergreen; they may be flattened as in hemlocks (Tsuga) or more rounded as in pines (Pinus).

Neuter: having no generative organs

Node: The portion of a stem where leaves and/or branches arise; often recognizable by the presence of one or more buds.

Not persistent: [Seed cones] {persistence} Falling from the branch soon after shedding seeds.

Not serotinous: [Seed cones] {serotiny} Having cones that open when the seeds ripen or soon thereafter.

Nucleus: an element of the protoplasm of most plant and animal cells that is regarded as an essential agent in their metabolism, growth, and reproduction and in the transmission of hereditary characters and that typically consists of a more or less rounded ma ss of nucleoplasm made up of a hyaline ground substance in which is suspended a network rich in nucleoproteins from which the mitotic chromosomes and one or more nucleoli condense, the whole being enclosed by a nuclear membrane

Nut: [Fruits] {type} A more or less large, dry fruit that does not split open at maturity (indehiscent), with a single inner chamber and a thick, bony wall surrounding a single seed, as walnuts (Juglans).

Nutlet: a small nut-like fruit (as of many plants of the family Boraginaceae)

Nutrition: Mode of acquiring substances necessary for growth and development.

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O

Obcordate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Heart-shaped with the point of attachment at the narrow end; inversely cordate.

Obdeltoid: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Similar in shape to an equilateral triangle, with the point of attachment at the narrow end; inversely deltoid.

Oblanceolate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Several times longer than broad, widest near the apex and tapering to a point at the place of attachment; inversely lanceolate.

Oblique: [Leaf bases, Leaflet bases] {shape} Having an asymmetrical base.

Oblong: (1) [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Shaped like a compressed oval, with the sides approximately parallel for most of their length. (Compare with elliptic.)

Oblong: (2) [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Shaped like an elongated ellipsoid, the sides almost parallel from near one end to near the other end.

Oblong-cylindric: [Seed cones] {shape before opening, shape when open} Intermediate in shape between oblong and cylindric.

Oblong-ovoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between oblong and ovoid.

Obovate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Egg-shaped with the point of attachment at the narrower end; inversely ovate.

Obovoid: [Seed cones] {shape before opening, shape when open} Egg-shaped with the base at the narrow end; inversely ovoid.

Obtuse: (1) [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} More or less blunt at the apex, with the sides coming together at an angle of greater than 90:.

Obtuse: (2) [Leaf bases, Leaflet bases] {shape} More or less blunt at the base, with the sides coming together at an angle of greater than 90:.

Ocellated [Leaf lower surface, Leaf upper surface] {color variegation} A broad spot of some color has another spot of a different color within it.

Ocrea: a tubular sheath around the base of the petiole consisting of a single stipule in the red clover or a pair of coherent stipules in the buckwheat family (Polygoniaceae)

Odd-pinnate: [Terminal leaflet] {presence} Pinnately compound with an odd number of leaflets, one of them terminal.

Once palmately compound: [Leaves] {complexity form} Compound with leaflets all attached at a common point and diverging from one another.

Once pinnately compound: [Leaves] {complexity form} Compound with leaflets attached at different points along and on either side of a central axis or rachis.

Once pinnately lobed: [Leaves] {lobing form} With several main segments or lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Once pinnate-pinnatifid: [Leaves] {complexity form} Once pinnately compound with pinnatifid leaflets.

Opposite: [Leaves] {insertion} Positioned in pairs along the stem, the members of each pair at the same level across from one another; two leaves occurring at each node.

Orbiculate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Approximately circular in outline.

Oval: (1) [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Broadly elliptic, the width more than one-half the length, with rounded ends.

Oval: (2) [Leaf cross section] {shape} Elliptic in cross section.

Ovary: [Flowers] The lower portion of a pistil where ovules are borne; often distinguishable from the rest of the pistil by its larger circumference.

Ovate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Egg-shaped in outline, with the broader end near the base.

Ovoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Rounded in cross section, broadest near a bluntly rounded base and convexly tapering to a narrower rounded tip; egg-shaped.

Ovoid-acuminate: [Buds] {shape} Egg-shaped but with the narrow end concavely tapering to a point.

Ovoid-conic: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between ovoid and conic.

Ovoid-cylindric: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between ovoid and cylindric.

Ovoid-ellipsoid: [Buds] {shape} Intermediate in shape between ovoid and ellipsoid.

Ovule: The structure in flowering plants and gymnosperms which when fertilized develops into a seed.

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P

Painted: [Leaf lower surface, Leaf upper surface] {color variegation} Colors disposed in streaks of unequal intensity.

Palea: This is a thin inner scale that encloses the developing seed in a spikelet of grass. The palea resembles a fertile lemma (the outer scale), but it is usually smaller and more difficult to observe. Not all species of grass have a palea as a structure in their flowers.

Palmate: (1) With three or more leaflets, lobes or other structures arising from a common point and diverging from one another; arranged or structured in a hand-like pattern.

Palmate: (2) [Leaf venation, Leaflet venation] {form} With three or more primary veins arising from a common point at or near the base of the leaf or leaflet blade.

Palmately lobed: [Leaflet, Leaves] {lobing form} With three or more main segments or lobes essentially arising from a common point near the base of the leaf or leaflet blade; lobed in a hand-like pattern.

Pandurate: [Leaflets, Leaves] {shape} Basically inversely egg-shaped (obovate), but with two opposite rounded sinuses in the lower half and two small basal lobes; fiddle-shaped.

Panicle: [Inflorescences] {type} A branched raceme, the main axis either determinate or indeterminate, and the lateral branches racemose; more loosely, a much-branched inflorescence of various types.

Pappus: A ring or pair of hairs, bristles, awns or scales attached at the top of the ovary just beneath the petals, persisting in fruit and often aiding in dispersal by wind or animals, especially in the Asteraceae.

Parallel: [Leaf venation, Leaflet venation] {form} With two or more primary veins that run more or less parallel from the base to the tip of the leaf or leaflet blade.

Parasitic: [Plants] {nutrition} Living in or on an organism of a different species and deriving nutrients from it.

Parietal: [Placentation] {type} Attachment of ovules on the inner wall, or intrusions of the wall, of a compound ovary with a single inner compartment (unilocular).

Pectinate: [Leaves] {habit} Arranged like the teeth of a comb, the leaves slender and more or less perpendicular to the stem; comb-like.

Pedicel: The stalk of a individual flower, either that of a solitary flower or of single flowers in a multi-flower inflorescence.

Peduncle: The main stalk of a multi-flower inflorescence or of a cluster of flowers within an inflorescence.

Peltate: [Leaf bases, Leaflet bases] {shape} Having the leaf stalk (petiole) attached to the lower surface of the leaf, usually near the center.

Pepo: [Fruits] {type} A specialized berry with a hard or leathery rind and a fleshy interior surrounding a mass of seeds, without interior sections or locules, as melons and cucumbers (Cucumis).

Perennial: continuing or lasting for several years--used specif. of a plant (as delphinium) that dies back seasonally and produces new growth from a perennating part

Perfoliate: [Leaf bases, Leaflet bases] {shape} Having the base completely surrounding the stem, so that the stem appears to pass through the leaf.

Perfoliate: Where the bases of two opposite leaves wrap completely around the stem. It is also possible for the base of an alternate leaf to wrap completely around a stem, but this is less common.

Perianth: The collective term for the outer sterile parts of a flower, comprising the calyx (sepals) and the corolla (petals) when both whorls are present.

Perigynium: the saclike bract that subtends the pistillate flower of sedges of the genus Carex and that in fruit becomes a flask-shaped envelope investing the achene

Perigynous: [Flowers] {perianth position} With the free portion of the perianth (the whorl of sepals and petals) borne at the top of a floral cup which is either a) fused to and partially encloses the ovary (the perianth thus appearing to arise at a level between the bottom and top of the ovary), or b) free from the ovary and extending up and around it to some extent.

Persistent: (1) [Petals, Sepals, Stipules] {persistence} Remaining attached; not falling off early, as stipules that remain attached while the leaves are attached.

Persistent: (2) [Seed cones] {persistence} Remaining on the branch long after shedding seeds, sometimes for many years.

Persistent (3) : [Seed cone armature] {persistence} Remaining attached; not falling off while the cone is still intact.

Petal: A unit or segment of the inner floral envelope or corolla of a flower; often colored and more or less showy.

Petaloid: resembling a flower petal in form, appearance, or texture

Petiolate: [Leaves] {form of attachment} With a leaf stalk or petiole.

Petiole: a slender stem that supports the blade of a foliage leaf and that is usu. cylindrical but sometimes flattened or even winged

Petiolulate: [Leaflets] {form of attachment} With a leaflet stalk or petiolule.

Petiolule: The stalk of a leaflet of a compound leaf.

Photosynthetic: Able to convert light energy to chemical energy by means of chlorophylls and other photosynthetic pigments.

Phyllary: one of the involucral bracts subtending the flower head of a composite plant

Phyllode: a flat expanded petiole that replaces the blade of a foliage leaf, fulfills the same functions, and is analogous to but not homologous with a cladophyll

Phytomelanin: a papery "sooty" black layer over the seed of plants in the Asparagales, which includes agaves, aloes, onions and hyacinths. It is an important character for defining the group.

Pilose: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With soft, more or less straight hairs.

Pinked: with a saw-toothed edge

Pinna: a leaflet or primary division of a pinnate leaf or frond

Pinnate: (1) With several leaflets, lobes or other structures positioned along and on either side of a central axis; arranged or structured in a feather-like pattern.

Pinnate: (2) [Leaf venation, Leaflet venation] {form} With secondary veins arising from a single, large midvein.

Pinnately lobed: [Leaflets] {lobing form} With several main segments or lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Pinnatifid: With several lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Pistil: The female or ovule-bearing organ of a flower, typically composed of an ovary, style and stigma.

Pistillate: [Flowers] {gender} Having functional pistils, but no functional stamens, making the flower unisexual and female.

Pith: The more or less soft and spongy tissue in the center of some stems and roots; sometimes degenerating to leave a hollow tube.

Placentation: The arrangement of ovules within the ovary.

Plane: [Leaf margins, Leaflet margins] {vertical disposition} With midrib and margin all in one plane, or nearly so; flat.

Plated: [Bark of mature trunks] {surface appearance} Bark with relatively large, more or less flat plates, as in mature loblolly pine (Pinus taeda) or mature white oak (Quercus alba).

Plumose: feathery, plume like. For example, wind-pollinated female flowers often have plumose stigmata so that they are more likely to receive the pollen of male flowers. Sometimes the hairs at the apex of a wind-dispersed achene (or seed) are called 'plumose' because they are branched and feathery in appearance, rather than straight and bristly

Pollen: The small, often powdery, grains which contain the male reproductive cells of flowering plants and gymnosperms.

Pollen cone: A male or pollen-producing cone; typically smaller and of shorter duration than seed cones.

Pollinium: (pl. Pollinia) the coherent mass of pollen grains that characterizes members of the Orchidaceae and Asclepiadaceae and often has a stalk bearing an adhesive disk that clings to visiting insects and facilitates withdrawal of the whole pollinium from its receptacle

Polygamous: [Plants] {distribution of gender} Having both bisexual (combined male and female) and unisexual (separate male and female) flowers or cones, which are borne on the same plant or on different plants of the same species.

Polyphyletic: derived (as by convergence) from more than one ancestral line

Pome: [Fruits] {type} A fleshy fruit that does not split open at maturity (indehiscent), with a more or less soft outer part derived from ripened hypanthium; the interior portion enclosing the seeds is divided into several sections or locules bounded by cartilaginous tissue; as apples (Malus).

Pore: a minute opening esp. in an animal or plant by which matter passes through a membrane

Poricidal capsule: [Fruits] {type} A capsule that develops openings or pores (dehisces), usually at or near the apex, through which the seeds pass to the outside; as in poppy.

Prickle: A small, sharp, non-woody structure developed from outgrowth of the surface of bark or epidermis.

Primary vein: A main vein in a leaf or other laminar structure from which other veins branch; the midvein or midrib when present.

Procumbent: being or having stems that trail along the ground without putting forth roots

Prophyll: a plant structure resembling a leaf (as a bracteole) or consisting of a modified or rudimentary leaf (as a foliar primordium)

Prostrate: trailing on the ground : PROCUMBENT

Pseudoterminal: [Buds] {position} Appearing to be the terminal bud, but actually the uppermost axillary bud with a subtending leaf scar on one side and the scar of the terminal bud often visible on the other side.

Puberulent: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With very short hairs.

Pubescence: The broad term for any type of plant hairiness.

Pubescent: [2-4-year-old twigs, Buds, Leaf lower surface, Leaf upper surface, Petals, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence} Bearing plant hairs (trichomes).

Pulp: the soft succulent part of fruit

Pulvinus: a cushionlike enlargement of the base of a petiole or petiolule consiting of a mass of large thin-walled cells surrounding a vascular strand and functioning in turgor movements of leaves or leaflets by reversible volume changes in the cells

Punctate glandular [Petioles, Rachises] {special surface features} Bearing sessile or embedded glands.

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