Achene: A dry, indehiscent fruit such as that of dandelion.
Acuminate: Tapering at the end, long-pointed.
Acorn: The nut or fruit of an oak that is attached to the tree by a cap or saucer.
Acute: Sharp-pointed, ending in a point.
Adpressed: Closely and flatly pressed against something.
Aleopathic: Producing a chemical that has herbicidal properties and can reduce the growth of another plant.
Alternate: Leaves and leaf buds are borne alternating along the stem.
Anastomosing: Connecting by cross veins and forming a network. Reticulate.
Andro-dioecious: Staminate and bisexual flowers on different plants.
Anther: The pollen-bearing portion of the stamen.
Aril: An accessory covering on a seed usually attached where the seed is attached to the stalk. The covering is often fleshy.
Armed: Bearing spines or prickles.
Auriculate: Having an auricle or ear-shaped lobe at the base of a leaf or other organ.
Axil: The upper angle that a petiole or other organ makes with the axis that bears it.
Axis: The main or central line of development of a plant or organ.
Axillary: Situated in an axil.
Berry: A fruit in which the whole pericarp is fleshy or pulpy.
Bipinnate: Twice pinnate.
Bisexual: Having both stamens and pistils and also known as a perfect flower.
Blade: The expanded part of a leaf or petal.
Bract: Modified or reduced leaf subtending a flower or flower cluster.
Capsule: A dry dehiscent fruit of more than one carpel.
Catkin: A scaly, bracted spike of usually unisexual flowers.
Carpel: A portion of the pistil or ovary. Simple fruits have a single carpel but compound pistils have two or more united carpels.
Caudate: Bearing one or more taillike appendages, often on the apex of a leaf.
Chambered: (Pith) Hollow except for solid partitions.
Ciliate: Fringed with hairs.
Codominant: Said of two branches or axes of equal size.
Cordate: Heart-shaped.
Corymb: A flat-topped or convex flower cluster with the outer flowers opening first.
Crenate: Toothed with shallow, rounded teeth.
Crown: The top of a tree including the branches and foliage.
Cultivar: A cultivated variety that is often reproduced asexually.
Cuneate: Wedge-shaped.
Cutover: Harvested especially by clear cutting or removal of all trees on a site.
Cyme: A convex or flat flower cluster of the determinate type, the central flowers open first.
Deciduous: (Foliage) Leaves that are shed in the fall, not persistent.
Decurrent: Extending down the stem into other structures. The habit of an elm or oak tree is said to be decurrent.
Decussate: Alternating in pairs at right angles.
Dehiscent: Opening to emit its contents, as a capsule.
Dentate: Toothed with the teeth directed outward.
Diaphragm: A cross partition at the nodes of hollow or pithy stems. Also used to designate cross partitions at the internodes of pith stems.
Dioecious: Staminate and pistillate flowers on different plants.
Drupe: A fleshy, indehiscent fruit with a bony, usually one-seeded endocarp like a peach.
Ecotype: A subspecies or race especially adapted to an environment.
Elliptic: With the outline of an ellipse, about two times as long as broad.
Elongate: Drawn out or longer than wide.
Emarginate: With a shallow notch at the apex.
Endocarp: The inner layer of the pericarp.
Even pinnate: A compound leaf with leaflets opposite each other on the petioles but without a terminal leaflet resulting in an even number of leaflets.
Excurrent: Branches are in whorls with a strong central leader resulting in a pyramidal growth pattern. Spruce trees and many other conifers have excurrent branching patterns.
Exfoliate: To separate or peel off in flakes, scales, layers, or sheets.
Exocarp: The outer layer of the pericarp.
Exotic: Not native but introduced from another country.
Falcate: Sickle-shaped. Flat and curved, coming to a point.
Fetid: Having a foul odor such as decaying flesh.
Fissure: A crack or crevice in bark resulting from trunk expansion and growth.
Floral bud: A bud that contains only reproductive or floral initials.
Flower: The reproductive structure of a plant.
Foliate: Leaflike. Said of a bud in which you can see that the winter buds are modified leaves.
Follicle: A dry dehiscent fruit, a carpel opening only along one suture.
Germination: The initiation of growth by a seed or other resting body such as a spore.
Glabrous: Not hairy.
Glaucous: Covered with a bloom, usually bluish-white or bluish-gray.
Gland: A secreting body or appendage, but often includes gland-like bodies.
Globose: Rounded or spherical.
Head: A dense cluster or short spike of sessile or nearly sessile flowers.
Hydric: (Site) Moist or swampy.
Imbricate: Overlapping, as shingles on a roof.
Indehiscent: Not opening.
Inflorescence: A single flower or a group of flowers.
Internode: The portion of the stem between two nodes.
Lanceolate: Lance-shaped, about four times as long as broad, the broadest portion below or above the middle.
Lateral bud: Buds that give rise to lateral branches and are not at the end of the twig.
Leader: Main axis of a tree or plant.
Leaflet: Part (blade) of a compound leaf. Pinna.
Leaf blade: The expanded part of a leaf.
Leaf scar: The scar left when a leaf falls or is shed.
Lenticel: Breathing pores appearing as warty dots or patches on the surface of the stem.
Linear: Long and narrow with nearly parallel margins.
Mesic: (Site) A site that is intermediate in moisture such as the side of a hill.
Mesocarp: The middle layer of a pericarp.
Midrib: The central vein or rib of a leaf.
Mixed bud: A bud that contains both vegetative and floral initials.
Monoculture: A planting or grouping of plants of a single species.
Monoecious: With separate male and female flowers on the same plant.
Monopodial: Having growth and elongation continuing indefinitely, often without branching.
Mucilaginous: Secreting a sticky or mucus-like substance.
Mucronate: Tipped with a short abrupt point.
Node: The place on the stem which normally bears a leaf or leaves.
Nut: An indehiscent, one-seeded, hard and bony fruit.
Oblanceolate: Inversely lanceolate. Longer than wide and widest above the middle.
Oblique: Said of a leaf where the two sides of the leaf are unequal in size and slanted at the base.
Oblong: About three times as long as wide and with nearly parallel sides.
Obovate: Inversely ovate and wider above the middle.
Odd-pinnate: A compound leaf with leaflets opposite each other on the petioles and having a terminal leaflet resulting in an odd number of leaflets.
Opposite: Leaves and axillary buds are borne directly opposite one another on the stem.
Oval: Broad elliptic, about 11/2 times as long as broad and rounded at the ends.
Ovary: The body which after fertilization becomes the seed.
Ovate: Egg-shaped and wider below the middle.
Ovoid: Egg-shaped.
Palmate: Radiately lobed or divided with three or more veins arising from one point.
Palmately compound: A compound leaf with leaflets arranged like the fingers on your hand.
Panicle: A compound inflorescence of the racemose type with pedicled flowers.
Papilionaceous: Butterfly-like flowers. Found in legumes with pealike flowers.
Pedicel: The stalk of a flower or later the fruit.
Peduncle: The stalk of a flower cluster.
Peltate: Said of a leaf where the petiole is attached inside the leaf margin.
Perfect: (Flower) having both stamens (male organ) and pistil (female organ), bisexual.
Pericarp: The wall of the ripened ovary.
Petiole: The leaf stalk.
Petiolule: The stalk of a leaflet in a compound leaf.
Pinna: A single leaflet of a compound leaf. Pinnae is the plural of pinna.
Pinnate: Compound leaf with leaflets placed on each side of the rachis.
Pistil: The seed-bearing organ of the flower consisting of ovary, style, and stigma.
Pistillate: Bearing one or more pistils, female.
Pod: A dry fruit, like a bean pod that opens on one side.
Polygamous: Bearing unisexual and bisexual flowers on the same plant.
Pome: A fleshy fruit with a core like the apple.
Prickle: A weak, thorny projection arising from the epidermis or bark rather than the woody tissue.
Pruinose: Covered with a waxy covering or bloom.
Pseudo-terminal: A false terminal. A bud that arose from a lateral bud when the terminal portion of the twig died and was shed. The scar may be very small.
Pubescent: Covered with short, soft hairs.
Raceme: A single inflorescence of stalked flowers on a more or less elongated rachis. The flowers at the base of the floral cluster open first.
Racemose: Having flowers in racemes.
Rachis: An axis bearing flowers or leaflets.
Regular: (Flowers) with the parts of each whorl alike.
Reniform: Kidney-shaped.
Resinous: Bearing or covered in resin or sap.
Reticulate: Netted or net-like.
Root crown: The region where the trunk transitions into the main or transport roots.
Root flair: Root crown.
Samara: An indehiscent flattened fruit that is normally winged as in maple or elm.
Scabrous: Rough to the touch.
Schizocarp: A dry fruit that breaks into halves such as a maple.
Seed: A ripened ovule consisting of the embryo and its integuments.
Serrate: Toothed.
Sessile: Not stalked.
Sinuate: Wavy surface or margin but differing from undulate in that it is wavy in and out.
Sinus: The recess between the lobes.
Spatulate: Spoon-shaped with a rounded tip and an acuminate base.
Spike: A simple inflorescence with the flowers sessile or nearly so on a common axis.
Spine: A sharp, pointed outgrowth of a stem, leaf, or other organ containing vascular tissue. Another term for thorn.
Stalk: The nontechnical term for an elongate support structure such as a pedicle or peduncle.
Stamen: The pollen-bearing male organ of the flower.
Staminate: (Flowers) Male flowers bearing only functional stamens.
Stipule: An appendage at the base of the petiole, usually one on each side.
Stomata: Orifices in the epidermis of a leaf.
Stomatic: Bearing stomata.
Stomatiferous: See stomatic.
Stone: The hard, usually one-seeded, endocarp of a drupe.
Strobile: An inflorescence with imbricated scales or bracts. A cone.
Subtend: Enclosed in the axil.
Superposed: One above another.
Suture: A line of dehiscence or groove masking a union.
Sympodial: Having the elongation of a stem or axis periodically interrupted with the elongation of a lateral.
Syncarp: A fleshy, aggregate fruit.
Terminal bud: The bud that is at the terminus of the twig is sometimes called the primary bud.
Ternate: In threes.
Thorn: A sharp modified stem usually arising from woody tissue and containing vascular tissue. Another term for spine.
Tomentose: Covered with short, dense, hairs.
Truncate: Ending abruptly as if cut off. Flat.
Umbel: An inflorescence with pedicels or branches arising from the same point.
Undulate: Wavy surface or margin. Used here as wavy up and down.
Unisexual: An inflorescence with flower of a single sex.
Valvate: Meeting at the edges without overlapping.
Variety: A population of plants below species that have similar characteristics and are usually reproduced from seed.
Vegetative bud: A bud that contains only vegetative initials such as leaves.
Villous: Covered with long, soft, usually curved hair. Hair is not matted.
Viscid: Sticky.
Whorled: Leaves and axillary buds are borne three or more at one point on the stem.
Woolly: Covered with long, dense, and often matted hairs.
X: A notation used before the genus or species denoting an intergeneric or interspecific hybrid.
Xeric: (Site) A dry site such as the top of a ridge.