Abscission layer – Layer of cells that forms at the base of each leaf petiole where it is attached to the twig when the veins that carry fluids into and out of the leaf gradually close off.
Acid soil – A description of the soil’s pH. Acidic soils have a pH below 7.0.
Acorn – The nutlike fruit of oaks.
Acuminate – Tapering to a point.
Acute – Short tapered, sharp tip, but less tapering than acuminate.
Alkaline soil – With a pH value of more than 7.0.
Alternate – Leaves that are staggered or not placed directly across from each other on the twig.
Anthers – Sac-like component of a flower where pollen grains are produced. The anthers open to release pollen.
Anthocyanins – Pigments in plants responsible for pink and purple colors.
Apex – The tip or growing point, the upper or outer end.
Aristate – The tip is a stiff, sharp bristle.
Axis -The central shoot of a compound leaf, cone, inflorescence, root, etc.
Bark – Outward covering of the tree.
Basal – Originating from the base.
Base – The point at which the leaf is joined to the stem.
Berry – A fleshy indehisent pulpy, succulent fruit with immersed seeds.
Bipinnate – Doubly or twice pinnate. (Bipinnately compound).
Blade – The broad, flat part of a leaf.
Bract – Modified leaf, generally associated with an inflorescence. Bracts may resemble normal leaves or be reduced and scalelike in appearance; they are sometimes large and brightly colored.
Broadleaf – A tree with leaves that are flat and thin and generally shed annually.
Calyx – The outermost whorl of sepals whose job is to protect a developing flower. It is usually green and is what we would recognize as the outside covering of a bud.
Cambium – Layer which forms across and between primary bundles where each year cells in this layer divide and grow. As the cambium divides, wood and bark cells form.
Capsule – Thin walled dry fruit containing 2 or more seeds and usually dehiscent.
Carotenoids – Pigments in plants responsible for yellow and orange colors.
Carpel – The female part of the center whorl of a flower. Also known as the pistil.
Catkin – Compact usually pendulous spike of unisexual flowers, as in birches, willows, poplars, oaks, walnuts.
Caudate – Having a slender tail-like appendage.
Chlorophyll – The green pigment in plants that absorbs energy from sunlight necessary for photosynthesis.
Chloroplast – The organelle in the cytoplasm of plant cells where chlorophyll is stored.
Chlorotic – Lacking in chlorophyll, typically yellow in color.
Clay – A minute soil particle less than .002 mil. in diameter.
Cleft – A leaf cut in about halfway to the midrib as in maple, liquidambar, sycamore.
Compound leaf – Leaf whose blade is divided into two or more distinct leaflets.
Cone – Conical woody fruit consisting of seed-bearing, overlapping scales around a central axis.
Conifer – Cone bearing tree or the pine family, usually evergreen.
Cordate – Heart shaped.
Coriaceous – Leathery in texture.
Corolla – The whorl of petals of a flower.
Crown – Parts of the tree above the trunk, including leaves, branches and scaffold, limbs.
Crownshaft – A tight bundle of very erect leaf bases that form a green pillar at the top of the woody trunk.
Cultivar – Cultivated variety. Maybe a field selection man-made cross or hybrid.
Cuneate – Wedge-shaped; triangular, with narrow part at point of attachment.
Deciduous – Shedding all its leaves seasonally, leafless for part of the year.
Deltoid – An equilateral triangular – attached at the center or one side.
Dentate – Having marginal teeth pointing outward, perpendicular to the margin.
Dioecious – Male and female flowers are borne on separate plants.
Doubly serrate leaves – Large teeth and small teeth alternating.
Drupe (stone fruit) – A fleshy one-seeded fruit which contains a single stone which in turn contains the seed.
Elliptic (leaf) – Elongately oval, about twice as long as wide, and broadest at the middle.
Emarginate– Having a shallow notch at the apex.
Entire Margins – Undivided and without teeth.
Evergreen – Trees with needles or leaves that remain alive and on the tree through the
winter and into the next growing season.
Falcate – Sickle shaped; asymmetric.
Fertilization – Joining of a sperm to an egg cell. Results in an embryo which triggers development of a seed.
Filaments – Thread-like structures that support the anthers out from the flower base.
Frond – Term used for the leaves of palms and ferns.
Fruit – The seed-bearing organ.
Glabrous – Hairless; smooth.
Hardscape – The sidewalk, curb, gutter, and street covering the soil surface.
Heartwood – The inner part of the wood; also called duramen.
Herbaceous – Non-woody plant, having the characteristics of an herb.
Indehiscent – Not opening to release its contents.
Inflorescence – The flowering part of a plant.
Lamina – The wide part of the leaf; also called the leaf blade.
Lanceolate – Shaped like a lance, much longer than it is broad, pointed at the tip and widest near the base.
Leaf – Outgrowth from the stem may consist of two parts, the stalk or petiole (when present) and the blade or leaf proper, which may be single (simple leaf) or divided into leaflets (compound leaf).
Leaflet – A segment of a compound leaf.
Legume – A dry pod-like fruit, belonging to member of the Pea Family, usually dehiscent, opening along longitudinal suture.
Lenticel – A small, usually corky area on a stem or other part of a plant, which acts as a gas exchange pore.
Linear – Long, narrow, and parallel-sided. Growing in one plane on a stem, like feathers.
Loam – Textural class name for soils having moderate amounts of sand, silt and clay.
Lobe – Any protruding part of an organ, as in an oak leaf. Having the edge of the leaf deeply but not completely divided.
Midrib – The central rib of a leaf or other organ.
Monoecious– Male and female flowers are borne on the same plant.
Mucronate– Having a small, hard point, as the projection of the mid rib of a leaf.
Node – The point on stem where one or more leaves and/or buds are attached.
Nut – A dry, usually large, indehiscent fruit with a thick, hard shell, usually one-seeded, and edible.
Oblong – Longer than wide with nearly parallel edges, wider than linear.
Obovate – Inversely ovate, broader at the tip, narrow near the stalk.
Obtuse – Having a blunt or rounded leaf apex.
Opposite – Leaf arrangement in which leaves arise in pairs at each node (directly across from each other); not alternate or whorled.
Oval – Broad-elliptic, about 1 1/2 times as long as broad and round at the ends.
Ovary – The inner part of carpel or pistil where eggs are borne.
Ovate– Egg-shaped, attached at the broad end.
Palmate – Having leaflets radiating out from a central point; veined, lobbed or divided as the fingers or a hand.
Palmately compound – Leaflets radiating out from a common point.
Pedicel (Pedicuncle) – The flower stem.
Peduncle – The stalk of a flower cluster.
Peltate – Shield shaped, with the stalk attached near the middle instead of the base or margin.
Pendulous – Hanging, weeping.
Perennial – A plant that lives for more than 3 years.
Perfect – A flower having both male and female parts (bisexual).
Petals – Outer part of a flower; protects the inside parts of a flower.
Petiole – Leaf stalk connecting leaf blade to the stem.
Phloem – A protective layer made up of tiny tubes that transport the sugars from the leaves to the rest of the tree.
Photosynthesis – The process by which plants make sugar from sunlight, water, and carbon dioxide.
Pinna (pl. pinnae) – The primary division of a compound leaf.
Pinnate – Having leaflets on both sides of a common axis, resembling a feather.
Pistil – Female part of a flower; also known as the carpel.
Pod – Dry, one-celled fruit, splitting along natural grooved lines, with thicker wall than a capsule, see Legume.
Pollination – The movement of pollen from a stamen to a pistil by pollinators (birds or insects).
Pome – Fleshy indehiscent fruit from a compound ovary.
Provascular tissue – Bundles of cells in young tree shoots.
Pubescent – Covered with very sort hair.
Revolute – The leaf margins are curved backwards or downwards towards the underside.
Root hairs – Threadlike extensions that grow from a plant root and takes in water and minerals from the soil.
Roots – Anchors the tree to the soil and absorbs water and soil minerals.
Sagittate – Arrowhead-shaped, with the basal lobes turned downward.
Samara – A dry, one-seeded fruit bearing a single wing.
Sapwood – The outer part of the wood; also called alburnum.
Senescence – Death of a leaf triggered by an increase in the enzymes that promote the breakdown of plant cells. Begins when shorter days and cooler temperatures occur.
Sepals – The separate parts of the flower calyx that is the outside covering of a bud.
Serrate – Saw-toothed.
Shrub – A woody perennial plant, usually with multiple stems, smaller than a tree.
Simple – A leaf with a single blade, undivided, unbranched, not compound.
Stalk – The stem or petiole or leaf, flower or other plant organ.
Stamen – The male part of a flower, consisting of a threadlike filament and a pollen-bearing anther.
Stigma – The sticky surface of a flower pistil on which pollen adheres during pollination.
Stomata – Openings in a leaf through which gases and water enter or leave.
Style – Extending from the center of a flower, it supports the stigma where pollen adheres during pollination.
Succulent – Juicy, fleshy, soft.
Syconium – A fleshy receptacle, which containS unisexual flowers borne inside the fruit, typical of the genus ficus.
Tannins – Pigments in plants responsible for brown colors.
Ternate – Arranged in threes.
Trees – Highly compartmented, woody, perennial, are usually tall, single-stemmed, and long-lived.
Whorl leaves -A group of three or more leaves arising at a single node.
Xylem – The main part of the tree trunk made up of tiny tubes which transport water and minerals from the roots up the trunk and branches to the leaves.