Glossary

Feeling lost when reading botanical descriptions? No worries! Look up new terms in the glossary:

Abaxial Lower surface.

Adaxial Upper surface.

Alternate [Arrangement of leaves or buds] Not opposite on sides of twig.

Awl-shaped [Leaf] Narrow and tapering to a sharp point.

Bisexual [Flower] Each flower has both male and female structures. They are also called perfect flowers.

Bole The main stem of a tree; usually the part that is commercially useful for lumber or other wood products.

Bract A leaf-like structure which is attached to a flower, a fruit or to its stalk.

Branchlet Shoot growth of the latest growing season.

Bur [Fruit] A prickly or spiny husk enclosing the seed.

Capsule [Fruit] A dry fruit enclosing more than one seed and splitting freely at maturity.

Catkin A compact, cylindrical cluster of flowers of the same sex.

Chambered [Pith] With hollow cavities separated by discs or plates.

Compound [Leaf] A leaf composed of smaller leaf units or leaflets.

Conical Wide at the base and gradually tapering to a point.

Conifer Cone-bearing trees; the “evergreens.”

Cordate Heart-shaped at the petiole end or base.

Corymb [Flower] A flat-topped floral cluster with outer flowers opening first.

Cyme [Flower] A flattened flowering structure, center flowers bloom earliest.

Deciduous [Leaves] All leaves drop in the autumn.

Diaphragmed [Pith] Solid but divided into sections by firmer discs.

Dioecious The plant has either only male or only female flowers. Word originates in Greek, meaning “two households.”

Drupe [Fruit] Fleshy outside, hard and stone-like inside; for example peach, mango, cherries.

Entire [Leaf] Margin of leaf without teeth, lobes, or divisions.

Fascicle [Leaf] A cluster of conifer leaves.

Glabrous Smooth, without hairs.

Glands Generally raised structures at the tips of hairs, or on a leaf, petiole, or twig.

Habitat The place where a plant usually grows.

Hardwood Term used to describe all broad-leaved trees, typically deciduous. Despite the term, some “hardwoods” have relatively soft wood, such as aspens.

Husk [Fruit] The somewhat leathery, outer covering of a fruit.

Imperfect [Flower] Flower is lacking some reproductive parts, such as stamens.

Invasive Not native to and tending to spread in a habitat or environment, sometimes displacing native species.

Leaf Stalk (petiole) and blade of hardwoods; needle-like and scales of conifers.

Leaflets Smaller leaf units which together form a compound leaf.

Lenticel [Bark] Raised pores on woody parts with openings for air-gas exchange.

Lobed [Leaf] With large, rounded or pointed projections along the leaf margin. Projections formed by indentations of the leaf margin.

Margin [Leaf] The edge forming the outline.

Midrib [Leaf] The large central vein.

Monoecious Flowers of both sexes appear on one plant (either unisexual or bisexual flowers). Word originates in Greek, meaning “one household.”

Opposite [Arrangement of leaves or buds] Directly across from one another on a common axis, or twig.

Panicle [Flower] A loosely branched, pyramidal cluster of flowers.

Petiole [Leaf] The stalk that supports the leaf blade.

Pith The central, soft part of the stem.

Prickle Extension of cortex and epidermis; for example Rose prickles.

Pubescent Covered with hairs.

Rachis The common stalk in a compound leaf to which the leaflets are attached.

Samara [Fruit] A dry, winged fruit; for example Maple fruit.

Scales [Bud] Small, modified leaves on the outer surface of buds.

Scales [Cone] The basic structures that enclose the seeds.

Scale-like [Leaf] Small, generally overlapping, triangular-shaped leaves of some conifers; for example Cedar or Juniper.

Seed That part of the fruit capable of germinating and producing a new plant.

Sessile Attached directly by the base without an intervening stalk.

Shrub A woody, many-stemmed plant, usually under 15 feet (4.5 m) in height at maturity, which branches from its base.

Simple [Leaf] A single leaf composed of a single blade.

Softwood Term used to describe all needle-leaved trees, typically evergreen. Larches are exceptions, being deciduous “softwoods.”

Solid [Pith] Without cavities or sections separated by discs.

Spike A flower stalk.

Spines Modified leaves, stipules, or parts of leaves.

Stipule A tiny, leafy, sometimes spiny projection arising at the base of a petiole.

Stomate (plural Stomata) Small pore on a leaf used for gas exchange.

Thorn Modified branches or stems.

Tree A woody plant, generally single-stemmed, that reaches a height of more than 15 feet (4.5 m) at maturity and a diameter of 3 inches (8 cm) or more measured at 4.5 feet (1.5 m) above the ground.

Whorl [Leaves or branches] More than two originating at the same level on a common axis.

Source: The Maine Forest Service. “Forest Trees of Maine” 2008.