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Abaxial
The side pointing away from the axis, usually the underside of a leaf, stem or branch.
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Abscission
The loss of a structure, such as a leaf, due to a chemical process where cells form a callous layer blocking food and water causing the structure to fall off.
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Accessory Bud
Buds that are not found in the axils of the leaves but are often found above or adjacent to axillary buds at a node.
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Acerose
Narrow elongated leaf; Needle-shaped.
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Acuminate
Sides curving concavely upward and inward then tapering to a fine point on the leaf apex.
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Acute
An angle that is less than 90º with straight lines and having a point on a leaf apex.
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Adaxial
The side toward the axis, usually the upper surface of a leaf, stem or branch.
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Alternate
Leaves or stems situated one at a node. Leaves can alternate in a distichous pattern 180º apart along two sides of the stem, or at lesser angles around a stem.
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Anther
A section of the male part of a flower containing the pollen.
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Apetalous
Lacking petals.
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Apex
The top; the terminal portion of a leaf; plural is apices.
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Apiculate
A leaf or petal having a short slender point that is flexible.
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Appressed
Firmly against another object, as a bud to a stem.
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Arching
Branches of shrub (or any part of plant) that curves outward from the main body of the shrub.
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Asymmetric
A plant part that has an irregular shape. (See also Oblique).
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Attenuate
Leaf tissue tapers down the petiole (toward the base) to a narrow base always having some fleshy leaf on either side of the petiole.
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Auriculate
Ear-lobed shaped leaf base(s) attached to petiole.
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Awl-shaped
Tapering to slender stiff point; Short stiff margins narrowing to a point, often sharp and found on young Junipers.
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Axil
The angled point on a stem where the leaf (or petiole) attaches to the stem.
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Basal
Beginning from the lower extremity of a plant part, as in leaves from the base of a stem.
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Base
The bottom; the proximal (nearest the stem) portion of a leaf (See also Apex).
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Bipinnate
Referring to a compound leaf where the pinnate leaflet has subdivided into smaller leaflets giving a more feather-like appearance.
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Blade
In trees, shrubs, vines and grasses, blade refers to the individual leaf; often referred to as Lamina.
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Bloom
White or waxy coating on the surface; also referred to as being glaucous.
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Bract
A modified leaf that is frequently showy and thought of as part of a flower; appears below actual flowers.
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Branch
A secondary stem that forks off of the main stem or trunk.
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Branchlet
A diminutive version of a branch; a small branch-like twig.
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Broad-oval
An ellipse that is less than twice as long as it is wide; Used often for habit and leaf but can be used for other descriptions.
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Broad-pyramidal
Pyramid shaped or triangular with a wider base than pyramidal.
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Broad-rounded
Nearly circular, but wider than tall.
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Bud
The unexpanded next season’s growth of leaves and flowers; undeveloped leaves and shoots.
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Bud Scale
One of the sheaths that cover a bud; There can be a few to very many;
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Bulbous
A tree bud that is rounded or ‘bulb-like’.
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Bullate
A raised blistered appearance between veins. Tissue near veins appears to pucker.
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Bundle Scar
Refers to the vascular bundles that are found in the scar left behind on a stem after a leaf falls off (abscises).
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Calyx
Outer part of the flower usually green and consists of the sepals; Plural calyces; (See also Corolla).
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Cambium
A meristematic layer of cells responsible for the growth of the bark and the wood.
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Capsule
Dry dehiscent fruit that has more than one carpel or ovule.
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Carpel
The female reproductive organ that consists of the stigma, style, and ovary.
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Catkin
A unisexual spike flower that is a long unbranched petal-free male or female flower with bracts between the flowers and that uses wind to spread the pollen; hangs down and can be ornamental.
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Ciliate
Fringe of fine hairs; can be found on leaves, stems, buds, flowers, etc.
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Collateral
Situated side-by-side; often in reference to multiple buds at a node.
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Columnar
Shaped like a column; much longer than wide and having a defined central leader.
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Compound
Divisions where there are two or more similar characteristics.
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Concave
Curved inward
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Cone
Woody cluster of seeds on a scale attached to a center axis; see also Strobile.
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Conical
Cone-shaped being taller than wide and attached at the wide end.
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Connate
The fusion of plant organs; such as sexual organs, leaves, petals, etc.
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Connate-perfoliate
Fusion of the bases of a pair of opposite leaves that attach directly to the stem (no petiole).
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Contorted
Twisted or bent in many directions; can appear on any part of plant.
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Convex
Curved outward.
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Cordate
Heart-shaped; can be overall leaf shape, or leaf base with the notched section connecting to the petiole.
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Coriaceous
Thick leathery texture of a leaf that is pliable.
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Corolla
The collective name for all of the petals of a flower; portions of the petals can be fused into a corolla tube (See also Calyx).
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Corymb
A flat-topped or round-topped indeterminate inflorescence with the lower pedicels growing to the same height as the upper and flowering first from the outside towards the center (See also Cyme and Umbel).
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Crenate
Rounded teeth along margin.
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Cuneate
Narrow wedge-shaped leaf base tapering to a point at the petiole.
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Cuspidate
Tipped with a short, abrupt point on a leaf apex narrowing to tip.
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Cyme
Flat-topped or round-topped determinate inflorescence; paniculate; terminal flower blooms first (See also Corymb and Umbel).
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Deciduous
A non-evergreen plant that loses it leaves after its growing season.
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Decumbent
A plant structure that grows along the ground with the tip curving upward (See also Prostrate).
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Decurrent
A leaf blade that attaches to and runs down the stem to the connecting point.
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Decussate
Leaves arranged in opposite pairs, rotating 90º at every node (See also Distichous).
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Dehiscent
An organ splitting open when ripe; commonly used for seed pods and anthers (for pollen release).
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Deltoid
Triangular like the Greek letter Delta, bottom two corners can be angular or rounded.
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Dentate
Square or rectangular teeth along margin pointing outward (See also Serrate and Crenate).
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Denticulate
Diminutive of dentate with very small square or rectangular teeth.
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Determinate
Predefined end of growth; in flowers the terminal flower blooms first stopping the elongation of the main axis.
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Dialated
Expanded or flaring open.
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Dichotomous
Veins extend from a common point forming a “y” pattern and fanning out as each vein branches into two.
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Dioecious
Plants that have all male or all female flowers but not both; often referred to as having “two houses”. Dioecious plants are thus either male or female.
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Dissected
A part of a plant that is deeply divided into narrow segments (See also Incised).
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Distichous
Leaves are arranged in two ranks along either side of a stem (See also Decussate).
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Divergent
Splitting or spreading apart.
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Divided
Split, cut, or lobed all the way to the base or midrib.
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Doubly-Serrate
Forward pointing teeth with each tooth (serration) having smaller serrations on it.
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Downy
Covered by a mass of small fine hairs that are soft.
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Elliptical
Narrow oval broadest in middle, narrow at the two ends; ellipse-shaped.
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Emarginate
The apex of the leaf is notched towards the petiole at the midvein.
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Entire
Continuous smooth margin, not toothed, notched, or divided.
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Epidermis
The outer layer of a non-woody plant (for a woody plant see bark).
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Even-pinnate
Pinnately compound leaf with a pair of terminal leaflets instead of one terminal leaflet resulting in an even number of leaflets. (See also Pinnate).
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Exfoliate
To peel or pull away from; such as bark on a tree.
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Falcate
Hooked like a sickle or beak of a falcon.
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Fascicle
A bundle or enclosure surrounding multiple parts (some evergreen needles, e.g. pines, are in a fascicle).
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Fasciculate
Multiple leaves appearing bundled in a fascicle (such as on a pine).
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Fastigiate
Branches erect and grown parallel, giving a broom-like appearance.
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Fetid
Foul-smelling, rancid.
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Fibrous Roots
Roots that are well branched, more thread-like, and scattered with no central leader (See also Taproot).
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Filament
The stalk of the stamen that holds the anther on a male flower.
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Flabellate
Fan-like, fan-shaped.
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Flower
Reproductive part of plant consisting of one or more of the following: stamens, pistils, sepals or petals.
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Foliage
All of the leaves of a plant.
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Foliose
Leaf or leaf-like; small unfurled leaves without a bud scale.
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Fringed
Decorative or stringy hairs along margin; can be seed, buds, leaves, etc (See also Tufted).
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Funnelform
Funnel shaped; increasing in size from the base to the apex.
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Glabrous
Hairless surface.
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Gland
An organ, projection, or tissue that sometimes performs special functions, like secretion of oils or sticky subtances.
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Glaucous
White or waxy coating on the surface often referred to as a bloom.
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Globose
Round or spherical in shape.
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Habit
The overall appearance or shape of a plant crown; a plant in silhouette.
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Habitat
The environment where a plant grows.
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Heartwood
The innermost part of a branch or trunk; usually darker in color than the sapwood.
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Hip
The term used for the berry-like fruit of a rose plant i.e. Rose hip; is actually a fleshy structure surrounding achenes.
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Hispid
Rough surface with stiff and bristly hairs.
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Hoary
Densely covered with short gray or white hair.
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Hypanthium
Cup-shaped structure formed from the fusion of the basil portions of the petal, sepals, and anthers; Usually surrounds the pistils. Commonly found in the Rosaceae family.
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Imbricate
Overlapping structures like shingles on a roof; e.g. scales on an imbricate bud.
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Impressed Venation
Veins sunken or below the surface of a leaf.
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Incised
Cut sharply, deeply, and irregularly into angular serrations along the leaf margin.
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Indehiscent
An organ, e.g. a fruit, that does not split open at maturity (See also Dehiscent).
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Internode
Part of the stem between two growing points or nodes.
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Involucre
Multiple bracts beneath a flower sometimes holding on into the fruiting stage as in acorn caps on oaks (Quercus).
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Involute
Margins rolled towards the top of the leaf.
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Keeled
A ridge running down the center of the bud scale; ridged like the keel of a boat.
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Lamina
The expanded portion of a leaf or petal; Refers to individual leaves (See also Blades).
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Lanceolate
Longer than wide with widest point below the middle tapering to both the apex and base. Narrower than ovate.
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Leaf Scar
Scar left behind on a stem after a leaf falls off (See also Abscission).
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Leaf Sheath
A covering or small stipule that covers part of a leaf.
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Lenticel
A small corky protrusion that allows for gaseous exchange between the air and the plant tissues.
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Linear
Long and thin like a line with parallel sides; length is more than 4 times the width (See also Oblong).
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Lobed
Rounded division or segment of a leaf or other organ. Can be symmetrical or asymmetrical and vary in sizes depending on species. Lobes are cut less than half way to the base or midvein.
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Lobulate
Small rounded lobes around leaf edges (See also Lobed).
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Low Spreading
A broad plant habit that hugs the ground (See also Prostrate).
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Lustrous
Shiny or glossy.
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Malodorous
Bad smelling.
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Meristem
A group of cells responsible for rapid cell growth and differentiation in specialized tissues.
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Midvein
The primary vein found in many leaves; Often it runs down the center of leaves.
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Monoecious
Both male and female flowers found separate on the same plant; flowers imperfect, both staminate and pistillate flowers borne on the same plant (See also Dioecious).
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Mucronate
Leaf apex tipped with short abrupt point on midvein.
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Multiple Fruit
A fruit formed from several flowers.
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Naked Bud
A bud lacking scales.
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Narrow-pyramidal
Tetrahedral; triangle that is taller than wide. Width is about half of height. Same as reticulate.
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Net-veined
Veins interlaced as in a network across the face of a leaf.
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Node
Point where new leaves or branches emerge (See also Internode).
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Obcordate
Inversely cordate; heart shaped; if it is a leaf apex, the petiole attaches at the narrow end.
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Oblanceolate
Inversely lanceolate; Much longer than wide with the widest point above the middle. Narrower than obovate (See also Lanceolate).
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Oblique
Unequal or asymmetric especially in leaf-blade or leaf base.
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Oblong
Two to four times longer than wide with nearly parallel sides.
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Obovate
Inversely ovate or teardrop-shaped; leaf connected to petiole at narrow end. Wider than oblanceolate (See also Ovate).
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Obtuse
Rounded leaf apex, greater than 90º at apex.
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Odd-pinnate
A pinnately compound leaf that ends in a single leaflet so that there is an odd number of leaflets (See also Even-pinnate and Pinnate).
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Opposite
Appear across from one another at the same node; opposite leaves may also appear decussate (each pair alternating at 90º angles at every node).
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Orbicular
Circular or rounded in leaf.
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Oval
Two times longer than wide with rounded ends.
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Ovary
The lower portion of the female pistil that contains the ovules (See also Stygma and Style).
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Ovate
Teardrop-shaped in outline and attached (to petiole) at the broad end; Wider than Lanceolate.
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Ovoid
A three dimensional part that appears egg-shaped; buds, fruits, etc.
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Palmate
Lobed, veined, or divided from a common point; usually 3 or more parts radiating from a common point; Veins, leaflets, lobes, etc.
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Panicle
A twice-branched, inflorescence maturing from the bottom towards the top.
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Parallel
Veins running nearly parallel; can be veins running parallel to the leaf axis or to each other.
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Pedicel
A stalk of an individual flower (See also Peduncle).
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Peduncle
A main stalk of an inflorescence from which the individual pedicels may arise. (See also Pedicel).
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Pendulous
Drooping or hanging downward.
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Perfect
A flower that has both pistils and stamens.
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Perfoliate
Leaf surrounds stem directly attaching to it; stem appears to go through the center of leaf; there is no petiole.
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Petiole
The leaf-stalk or axis connecting the leaf to the stem.
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Petiolule
The stalk or axis of the leaflets in a compound leaf .
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Pinnate
Parts arranged along opposite sides of an axis; A leaf with a prominent midvein and veins along both sides of the midvein; Compound leaf with leaflets arranged along opposite sides of a petiolule or leaf stalk.
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Pistil
The female part of the flower typically consisting of a stigma, style, and ovary. Commonly referred to as the gynoecium (See also Stamen).
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Pith
The spongy tissue in the center of a stem or root (consisting of parenchyma cells).
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Polygamo-dioecious
Mostly dioecious, but with some perfect flowers. (See also dioecious).
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Polygamo-monoecious
Mostly monoecious, but will some perfect flowers (See also dioecious).
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Polymorphic
Many shaped.
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Prickle
A small sharp growth arising from the epidermis (See also thorn).
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Procumbent
Growing or following along the ground, but not rooting where it touches.
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Prostrate
Lying flat along the ground.
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Puberulent
Diminutive of pubescent; having fine short hairs.
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Pubescent
The surface of leaf or stem is covered with short fine hairs.
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Pyramidal
Triangular-shaped that is taller than wide with the width being 2/3 the height.
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Raceme
A once-branched inflorescence that flowers from the bottom up (See also Panicle).
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Rachis
The main axis of a compound leaf or inflorescence.
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Radial
Parts arranged around a common center point.
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Recurved
Bent or curved backward.
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Reflexed
Bent abruptly backwards or downwards.
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Resinous
Having or containing resin; being sticky.
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Reticulate
Appearing like a net, or network (See also Net-veined).
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Revolute
Margins rolled downward towards underside of leaf.
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Rhombic
Diamond-shaped with 4 sides; petiole attached at one of the corners.
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Rhizome
An underground stem, distinguishable by the presence of nodes, buds, or leaves (See also Stolon and Tiller).
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Rosette
Radiating cluster of leaves.
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Rounded
Wide curved shape that is wider than Obtuse with less of a point, while not being so flattened as to approach Truncate.
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Rugose
A wrinkled surface as on a leaf.
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Sapwood
The outer and lighter wood that is actively transporting water.
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Scabrous
Rough texture due to short stiff hairs or the epidermal cells.
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Scale
A small dry bract acting as a covering or layer.
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Scale-like
Having small overlapping layers.
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Schizocarp
A dry dehiscent fruit that breaks apart into two halves.
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Scurfy
Covered with small bran-like scales.
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Serrate
Sharp forward-pointing teeth along leaf margin.
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Serrulate
Many minute sharp forward-pointing teeth along leaf margin.
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Sessile
Attached directly without a stalk; a leaf or flower directly attached to a stem.
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Shoot
A young green stem.
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Shrub
A small woody plant with multiple stems from the ground and that is not usually climbable; all of the branches are produced from or near the base.
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Simple
A single undivided leaf. A simple leaf may have lobes, or serrations (See also Compound).
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Sinuate
Strongly wavy margins only in one plane; close to being lobulate (See also Undulate).
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Sinus
On a lobed leaf a sinus is the valley between the lobes; they can vary greatly in size and shape.
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Spatulate
Spoon or spatula-shaped, with a rounded leaf blade that tapers to the base.
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Spinose
Bearing spines along leaf margins, Tiny spines at nodes on stems.
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Spike
An inflorescence that is unbranched with sessile flowers maturing from the bottom up.
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Spine
A hard sharp woody growth that emerges from below the epidermis and is either a modified leaf or stipule (See also Thorn).
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Spinose
Having spines; having sharp woody growths.
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Spirally Arranged
The actual pattern of alternate leaves on a stem;
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Spur
A short shoot with leaves or fruit. Ex. Ginkgo; A hollow projection from a flower either in the sepals or petals.
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Stalk
A supporting structure for a leaf, flower, or fruit.
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Stamen
The male part of a flower typically consisting of an anther and filament; Commonly referred to as the androecium. (See also Pistil)
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Stem
Supportive structure for buds, leaves, and nodes; can be single or branched; sometimes found underground.
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Sterile
Barren or infertile; not able to produce seed.
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Stigma
The recepticle for pollen on the pistil.
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Stipule
A bract or appendage at the base of a petiole (usually found in pairs).
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Stolon
A horizontal stem that roots at the nodes and tip and can produce a new plant (See also Rhizome and Tiller).
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Strobile
A cone or an inflorescence resembling a cone. Ex. Alders
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Style
The tube that connects the stigma and ovary of the pistil (the female part of the flower).
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Subopposite
Leaves appear near opposite but slightly skewed at a node without a fascicle (See also Opposite and Alternate).
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Superposed
Appearing one right above another; an accessory bud found above the true bud.
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Symmetric
A balanced appearance; Having the same number of floral parts in any angle.
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Taproot
A central root that has smaller fibers coming off of it (See also Fibrous root).
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Tendril
A twining stem that supports a vine.
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Terminal
The end or tip of a part (See also Basal).
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Thorn
A hard sharp modified stem; can branch and have leaves and buds (See also Spine and Bristle).
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Tiller
A stiff basal or underground shoot that is mostly erect (See also Rhizome and Stolon).
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Tomentose
Covered in a mat of short soft hair
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Trace
The scar of the veins left behind when the leaf falls off (abscision), located within a leaf scar.
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Tree
A large woody plant typically with a main trunk.
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Truncate
Leaf base or apex is perpendicular to leaf petiole and relatively straight across
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Trunk
The main stem of a tree.
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Tufted
A clump of hairs that are arranged in a dense cluster (See also Fringed).
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Twig
A branch or shoot from a shrub or tree.
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Twining
A stem that spirals around another object for support.
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Two-ranked
Aligned in two rows on opposite sides.
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Two-scaled
Two scales on a bud.
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Umbel
A flat-topped inflorescence with the pedicels (flower stalks) arising from one point (See also Corymb and Cyme).
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Undulate
A leaf margin that has upward and downward waves in it giving the leaf a more three-dimensional appearance (See also Sinuate).
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Vase-shaped
The habit of a shrub or tree which begins narrow and widens out the higher you go.
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Valvate
Two organs meeting without overlapping as in many leaf buds.
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Variegated
Striped, mottled, or bordered color on a what normally would have been solid.
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Vascular bundle scar
The scar left where the vessels were found within the leaf scar; Similar to Trace.
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Venation
The pattern of the veins in a leaf.
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Vine
A climbing or trailing plant that is not supported by the stem but by some other sort of fastening (i.e. tendrils).
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Volute
Rolled up (See also Involute and Revolute).
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Warty
A bumpy, rough surface texture.
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Weeping
Hanging down or pendulous.
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Whorled
Three or more leaves arising at a node.