Achene — A small, dry, one-seeded fruit
Acuminate — Tapering gradually to a point.
Acute — Tapering rapidly to a point.
Alternate — Plant parts that are placed individually along a stem, in a zigzag arrangement, one leaf at each node, not opposite each other.
Angiosperm — A class of plants characterized by the formation of flowers and seeds enclosed in fruits.
Apex — The extreme top or tip of a plant part.
Appressed — Pressed closely and flatly along the length of a plant part.
Arcuate — Arching, as in leaf venation when veins arch from the midrib and follow the margin back to the tip of the leaf.
Axil — The upper angle formed by a leaf petiole with the stem.
Bark — The tissues formed on the outside of a woody stem.
Base — The bottom portion of an object.
Berry — A fleshy fruit without a stone, usually containing many seeds embedded in the pulp.
Bipinnate — More than one set of leaflets per leaf.
Blade — The flat, expanded portion of a leaf.
Bloom — White, powdery layer on plant parts. Usually easily rubbed off.
Branch — One of the divisions of the trunk.
Bristle — A stiff, thin hair which may be straight or hooked.
Bud — The undeveloped state of a branch, leaf and/or flower cluster, with or without hard scales.
Bud Scale — Modified leaves forming a covering which protects the bud from drying out and other injuries.
Bundle — A cluster of plant parts.
Bundle Scar — Marks within the leaf scar produced when the petiole separates from the stem, indicating the broken ends of the xylem and phloem strands.
Capsule — A dry fruit with many seeds, opening near the tip.
Catkin — A slender, pendulous, dense flower cluster.
Chambered — A solid pith that is interrupted by uniformly spaced partitions of hollow spaces.
Collateral — Being side by side, as in buds on a stem.
Compound — The leaf blade is divided into several separate sections called leaflets.
Concave — Depressed or hollowed out.
Conifer — A cone-bearing tree or shrub.
Continuous — Solid, no cavities or hollow spaces.
Convex — Arched
Cordate — Heart-shaped.
Crenate — A leaf margin with rounded, shallow teeth.
Crown — Upper part of a tree, the living branches with their foliage.
Deciduous — Plant having all leaves that fall off each year (fall).
Deltoid — Triangular.
Dentate — Sharp teeth of leaf margin pointed out, not forward.
Dissected — Finely divided.
Divergent — Bud stick out, point away from stem.
Downy — Plant part is coated with soft hairs.
Elliptic — Widest at the middle, tapering equally to each end.
Entire — Leaf edge (margin) has not indentations or teeth at all; completely smooth.
Evergreen — A woody perennial bearing foliage throughout the year.
Exfoliate — To peel or flake off in thin layers.
Flower — Reproductive organ of an angiosperm.
Fluted — Regularly marked by alternating ridges and grooved-like depressions.
Fruit — A ripened, mature ovary.
Furrowed — Longitudinal ridged and grooves.
Glabrous — No hairs, bristles, or scales. Smooth.
Gland — A tissue or protruding structure secreting oils, balsams, or resins; usually on a leaf or petiole.
Glaucous — Smooth and covered with a fine, white or blue powder (bloom) which can be rubbed off.
Globose — Round in form, or nearly so.
Granular — Minutely roughened.
Habit — General appearance of a plant as seen from a distance.
Herbaceous — Not woody; soft tissues.
Imbricate — Overlapping, like shingles on a roof.
Internode — The space between nodes that is lacking leaves and buds, such as on a stem.
Keeled — A prominent central ridge, like the keel of a boat.
Lanceolate — Tapering gradually from the base to a point; narrow and long.
Lateral — Situated or produced on the side.
Leaf — Appendage of a stem composed of a flat, veined blade, and a stalk attaching the appendage to the stem.
Leaf Scar — Scar left on the stem at the point where the leaf fell off.
Leaflet — One of the small, individual blades of a compound leaf.
Lenticel — A small breathing pore on the stem of plants, may be showing up as a different colored dot on the stem, somewhat corky.
Linear — Long and narrow with nearly parallel sides.
Lobe — Rounded or pointed extensions of the leaf blade margin.
Lustrous — Shiny, glossy.
Margin — The very edge of a leaf blade.
Midrib — The mid or central vein of a leaf.
Naked Bud — Lacking a covering, as in a bud with no protective hard scales.
Needle — Very narrow leaf, as in conifers.
Node — The place on a stem where buds and leaves arise, usually a swollen area on the stem.
Oblanceolate — Long and narrow but broadest near the tip.
Oblique — Lopsided.
Obovate — Egg-shaped, broadest near the tip.
Obtuse — Blunt at the tip, almost rounded.
Opposite — Plant parts arise opposite each other along a central axis.
Ovate — Egg-shaped, broadest below the middle.
Palmate — With divisions spreading from a common center.
Panicle — A branched flower cluster, the lower branches longest and flowering first.
Pendulous — Hanging down, drooping.
Persistent — Remaining attached, not falling off after the growth period.
Petiole — The leafstalk which attached the leaf blade to the stem.
Petiolule — The leafstalk of a leaflet in a compound leaf.
Pinnate — Leaflet or veins arranged on each side of a common stem; feather-like.
Pith — The central-most, softer portion of a stem.
Prickle — A needle-like outgrowth arising from the outer layer of stem, leaf or fruit cell (example: rose thorn).
Pubescent — Hairy or downy.
Rachis — The leafstalk of a compound leaf.
Reflexed — Abruptly bent or turned downward.
Resin — An excretion production of certain plants.
Reticulate — Net-like, many small irregular veins throughout a leaf.
Revolute — Rolled back toward the lower side, as in a leaf margin.
Root — Underground part of a plant which supplies the plant with nourishment, anchors the plant, and is a storage area.
Rugose — Coarsely wrinkled, uneven, rough.
Samara — A dry, winged, on-seeded, papery fruit.
Scabrous — Rough to touch.
Serrate — Leaf edge (margin) composed of teeth pointing toward the tip of the leaf.
Sessile — Without a stalk, sitting directly on the base.
Sheath — A tubular envelope, possibly papery, clasping and enclosing other plant parts, such as the needles of a pine.
Shoot — A stem bearing foliage.
Shrub — A woody perennial usually having many trunks.
Simple — In one piece; not divided into smaller units.
Sinus — The recesses or indentations between two lobes.
Spine — A sharp, thin modified leaf, arising form a node on the stem, just like a leaf would (example: cactus).
Spur Shoot — A short, stubby branch bearing leaves, flowers or fruit.
Stellate — Star-shaped.
Stem — The leaf and flower-bearing part of a plant.
Stipule — A leafy appendage at the base of a petiole, usually one at each side.
Stipule Scar — The scar left on the stem when the stipules fall off.
Stomata — Breathing pores in leaves.
Strobile — A small cone or cone-like structure.
Sub-opposite — Almost opposite, not quite.
Sucker — An extra shoot arising above ground from a root.
Superposed — One bud above another.
Tendril — A modified leaflet, leaf, stipule, or branch used as a lateral climbing organ by the plant.
Terete — Circular in cross section.
Terminal — Situated at the end or tip.
Terminal Bud Scar — The scar remaining on a stem after a bud has elongated and the bud scales have fallen off.
Thorn — A modified stem, hard and sharp-pointed, arising from a node (example: Hawthorn).
Tomentose — Densely woolly, hairy.
Tree — A woody perennial with one main trunk.
Trifoliate — Three leaflets, or leaves arranged in threes.
Valvate — Meeting at the edges, not overlapping
Vein — A strand of conducting tissue in a leaf. Continuation of the xylem and phloem from the stem, through the petiole, into the leaf.
Venation — Arrangement of veins within the leaf.
Whorl — The arrangement of leaves in groups of three or more at nodes.
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