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