Abscission — The shedding of flowers, leaves, and fruit following formation of scar tissue in a plant. Also, it is the act of cutting something off.
Absorbing Roots — Fine fibrous roots that take up water and minerals; most of them are within the top 12 inches (30 centimeters) of soil.
Acidic — Soil with a pH less than 7.0. The lower the pH the more acidic or sour the soil. Sulfur is typically added to make the soil more acidic. Acidity can also occur naturally in forested areas or as a result of leached soils.
Aggregate — One formed by the coherence or the connation of pistils that were distinct in the flower when the pistils of separate flowers make up the fruit;designated as a multiple fruit.
Alkaline — Soil with a pH greater than 7.0. The higher the pH the more alkaline, sweet or basic the soil. Lime is typically added to the soil to make it more alkaline.
Alternate — Of leaves and branches etc; first on one side and then on the other in two ranks along an axis; not paired; "stems with alternate leaves".
Apetalous — Having no petals.
Arboretum — A place where an extensive variety of woody plants (trees), are cultivated for scientific, educational, and ornamental purposes.
Arboriculture — The study of trees and other plants.
Ascending — Growing upwards in a gradual curve to an upright position.
Axils — An angle between a branch or leaf, and the stem from which it moves up from.
Bell-shaped –- The tree or plant leaf that is shaped like a bell.
Bigness Index — A number given to large trees based on circumference in inches plus height in feet plus span in feet divided by 4.
Bipinnate — Double pinnate; see Pinnate.
Borers — Any insects or larva that drill into plants.
Bract — A leaf from the axil of which a flower or floral axis will arise. The red Poinsettia, a common December floral decoration, is an example of a bract.
Brittle — Brittle wood is easily broken, or more likely to break than softwood or hardwood. Commonly known trees with brittle wood are the Siberian Elm, Silver Maple, Cottonwoods, Poplars, and Willows.
Calyx — The outer part of the flower, usually green and formed of several divisions called sepals, that protects the bud.
Cambium — Layer(s) of meristematic cells that give rise to the phloem and xylem and allow for diameter increase in a tree.
Canker — Dead sections of bark on branches or main trunks of trees. Bacteria, fungi, or mechanical damage are all possible causes for canker to form.
Catkin — A cluster of flowers that forms a long, skinny, caterpillar-like shape is called a "catkin".
Cluster — A number of things of the same kind growing together; a bunch.
Compartmentalization — Natural process of defense in trees by which they wall off decay in the wood.
Concentric — One or more circles within each other, having the same center point.
Cones — A mass of ovule-bearing (seed), pollen-bearing scales or bracts in trees of the pine family (Pinus), on a somewhat elongated axis. A pine cone is an example of a cone.
Conical — Shaped like a cone.
Conifer — A tree that produces cones, such as a pine, spruce, or fir tree.
Convulsions — Any violent or irregular motion.
Corky — Wood that is dry and full of holes. Like that found in the outer layer of tree bark.
Corolla — The petals (or petal) that make up the flower. These may be united into a tube or other structure.
Corymb — A generally flat-topped flower cluster with pedicels varying in length, the outer flowers opening first.
Crown — The aboveground portions of a tree.
Cultivar — A variety of a plant developed from a natural species and maintained under cultivation.
Cyme — A more or less flat-topped determinate infloresence whose outer flowers open last.
Cypress Knees — Cypress “knees” are cone-like structures that are actually part of the Cypress tree. They protrude out of the ground or water, and grow upward from the wide spreading root systems of the Cypress tree.
Deciduous — Shedding foliage at the end of the growing season.
Decomposing — The process of breaking down into the elements or parts that make up the whole. Rotting is an example of decomposing.
Dehiscent — Splitting open along regular lines, as in a fruit which breaks open at maturity to release its contents of seed.
Dioecious — Plant with unisexual flowers. Each sex is confined to separate plants.
Dissectum — Divided into narrow, slender sections, such as the cutleaf type Japanese Maple.
Divergent wings — An out-growth usually on stems. Flat woody growths resembling shape of the insect wings, growing apart from a single connection.
Dormant — State of reduced physiological activity in the organs of a plant.
Drip Line — Perimeter of the area under a tree delineated by the crown.
Drupe — A fleshy fruit containing a single seed in a hard "stone" (e.g. Peach).
Evergreen — A plant having foliage that persists and remains green throughout the year.
Exfoliating Bark — Bark that peels off the outer surface of the trunk and branches in thin flakes, scales, or layers.
Fascicle — A small bundle, e.g., 2 to 5 needles per cluster in pines.
Fibrous — Having long narrow shreds or flakes.
Fissured — Bark that forms a net-like pattern from splitting of the outer and inner bark.
Flaked — The bark is separated into flat, thin pieces or layers; flakes.
Focal-point — A point from which branches extend in different directions from a common point.
Follicles — A dry dehiscent fruit opening only along one suture and the product of a single carpel.
Fossil — Formerly all minerals were called fossils, but the word is now restricted to express the remains of animals and plants found buried in the earth.
Furrowed — A groove or growth that builds on top of itself selectively. Growth of plant material in an inconsistent manner to cause irregular height and depth along its surface, causing grooves and ridges. Bark that is deeply or shallowly grooved.
GIS — Geographic Information System. A specialized database for storing and manipulating geographic information.
Glaucous — Covered with a waxy bloom or whitish material that rubs off readily.
Glossy — A surface luster or shiny appearance. A natural secretion of plant material that gives a shiny appearance to the surface.
GPS — Global Positioning System. A satellite-based navigation system used for determining someone or something's precise location and providing a highly accurate time reference almost anywhere on earth.
Harbinger — To signal the approach of, or foreshadows what is to come.
Hardwood — A term used in reference to the relative hardness of wood in a tree. Examples of hardwoods include the oaks, hickories, and ashes.
Heartwood — Inner, nonfunctional xylem tissues that provide structural resistance to the trunk.
Honeydew — Substance secreted by certain insects when feeding upon plants.
Imperfect — Flowers having either stamens (male) or pistils (female) but not both.
Inflorescence — A characteristic arrangement of flowers on a stem. A flower cluster.
Involucre — Leafy structure found surrounding the fruit of different plant species to aid in protection and development. Kidney-shaped — An organ of the human body, the kidney has a distinct shape repeated in nature—round curve with one side circular and the other with a concave indention.
Lenticel — A small corky spot on young bark made of loosely packed cells, providing gaseous exchange between the inner tissues and the atmosphere.
Medicinal — It is the power to check or cure diseases.
Midrib — The central and main vein of a leaf.
Monoecious — A plant with both sexes on the same plant.
Mottled — An irregular pattern of patches or spots of different colors.
Obovate — Of a leaf shape; egg-shaped with the narrower end at the base.
Opposite — Growing in pairs on either side of a stem; "opposite leaves".
Ornamental — Something that serves as ornamentation, a plant grown for its beauty.
Ovule — The structure within the ovary that will become the seed after fertilization.
pH — A measure of acidity or alkalinity of a medium.
Panicle — A branched cluster of flowers in which the branches are racemes.
Paralysis — The inability to move or function.
Pathogen — Causal agent of disease.
Pedicel — The stalk of one flower in a cluster.
Pendulous — Hanging loosely; suspended so as to swing or sway.
Peduncle — A stalk bearing an inflorescence or solitary flower.
Perfect — A flower that has both functional stamens and pistils.
Petiole — The stalk or support axis of a leaf.
Pharmaceutical — The art of preparing medicines according to the rules or formulas of pharmacy.
Phloem — Tissue that conducts synthesized food substances (e.g., from leaves) to parts where needed; consists primarily of sieve tubes.
Pinnate — Compound leaf with leaflets along each side of a common axis.
Pistillate — A flower bearing a pistil or pistils, but not stamens, may refer also to a plant having only pistillate flowers.
Pods — Usually referring to the legume family, a pod is composed of one folded carpel. Pods hold the forming seeds and open when seeds mature. A sweet pea is an example of a pod.
Polygamodioecious — A species that has male flowers and female flowers on separate plants, but each of these types of plants has perfect flowers as well.
Pome — Fleshy fruit with a core, such as a crabapple.
Profusely — Something that is given freely and/or abundantly.
Pubescent — Covered with short, soft hairs.
Pulpy — A mass of soft plant tissue. Apples have a pulpy texture.
Pyramidal — Square-base meeting at a point; built up in shape like a pyramid.
Raceme — A group of flowers similar to a spike, but with each individual flower on its own stem.
Reflexed — To bend backward or bend something back.
Resin — Resin is a substance exuded as a protective mechanism against disease and insect infestation by trees. Amber is a form of tree resin that has hardened and been preserved in the earth's crust for millions of years.
Resistant Varieties — Plants the are tolerant of, or not susceptible to, certain disease or pest problems.
Samara — A type of fruit that is dry, not splitting open at maturity, winged, often one-seeded. Like the fruit of the Ash, Elm, or Maple.
Sap — Sap is the watery fluid (sugars) produced by the leaves to supply food for the tree. It circulates through a tree, carrying food and other substances to the tissues.
Sapwood — Out wood that actively transports water and minerals.
Scaly — The bark is separated into flat, thin pieces or layers; scales.
Scorch — Browning and shriveling of foliage, especially at the leaf margin.
Sepals — The outermost flower structures which usually enclose the other flower parts. This part of the calyx is usually green, but can sometimes be brightly colored.
Serrate — Sawtooth margin of a leaf with the teeth pointed forward.
Sessile — Without a stalk; sitting directly on its base.
Shedding — To cast off a growing part, such as leaves, as a result of a natural process.
Shield-shaped — A shape in nature resembling a warrior’s shield. Many flowers are shield-shaped.
Simple — A single, one-part leaf that is not composed of leaflets.
Sinuses — The opposite of a lobe, the sinus is the part of a leaf that dips toward the center.
Softwood — Softwoods are conifers, evergreen and cone-bearing trees. Softwoods include cedar, fir, hemlock, pine, redwood and spruce. They are usually used as structural lumber such as 2x4s and 2x6s, with limited decorative applications.
Soil Compaction — Compression of the soil resulting in a reduction of the total pore space, especially the macropores.
Spike — A usually elongated, unbranched inflorescence with stalkless flowers arranged along an axis.
Spikelet — A small or secondary spike, characteristic of grasses and hedges. It usually has a varying number of reduced flowers, each subtended by one or two scale-like bracts.
Spreading — To extend or grow outward from a trunk or center. To extend in length and breadth, or in breadth only; to stretch or expand to a broad or broader surface or extent; to open; to uncurl.
Spurs — Sharp points that prick or a tubular or sac-like extension of the corolla or calyx of a flower.
Staminate — A flower or plant that has only stamens. A male plant or flower.
Stoma — A microscopic opening in the surface of a leaf that allows gases to pass in and out.
Striated — Marked by narrow lines or grooves, usually parallel.
Sucker — Shoot arising from the roots.
Sunscald — An overexposure to sun, primarily in the winter, seen on the south or southwest sides of the main stem.
Syncarp — A fleshy, aggregate fruit.
Tannin — A brown pigment found in leaves and other parts of plants. It causes the brown color of leaves after all other colors have disappeared. It is present throughout the growing season but is masked by the chlorophylls (greens), xanthophylls and carotenes (yellows and oranges), and anthocyanin (reds and purples). Tannin solutions are acid and have an astringent taste.
Terminal twigs — Twigs growing at the end of a branch or stem.
Tiered — Step like series of rows that are set one above another; rises.
Tolerance — To prevent the effects of certain things.
Toothed margins — A formation resembling the toothed edge of a saw.
Trifoliate — Three-leaved.
Tubular -– The tree or plant leaf is shaped like a tube.
Umbel — A flower cluster with all the flower stalks radiating from a central point.
Upright — In an erect position or posture; perpendicular; vertical, or nearly vertical; pointing upward; as, an upright tree.
Warty — Bark has protruding wart-like projections.
Water Shoot — A secondary, upright shoot arising from the trunk, branches, or roots of a plant.
Watersprout — An upright, adventitious shoot arising from the trunk or branches of a plant; although incorrect, it is also called a sucker.
Whorled — Forming one or more whorls (especially a whorl of leaves around a stem).
Woody — It contains wood or wood fibers in the bark.
Xylem — The woody part of plants: the supporting and water-conducting tissue, consisting primarily of tracheids and vessels.
Zigzag — A series of short sharp turns; to cause to move in or form a zigzag.
Information about CITYgreen was used with permission from Mike Lehman, Director of Sales, CITYgreen Software
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