tree leaf identification glossary

One aspect of tree leaf identification, I thought it may be good to take a look at, would be the terms in use.

ALTERNATE

leaves that are staggered, not placed directly across from each other on the twig.

BLADE

the flat part of a leaf or leaflet, characteristic of broadleaf trees.

BRACT

a modified leaf that bears a flower.

BROADLEAF

a tree with leaves that are flat and thin, and generally shed annually.

BUD SCAR

the marks remaining after bud scales drop in spring.

CAMBIUM

A single layer of cells in the tree’s trunk that produces the new wood and bark

COMPOUND LEAF

a leaf with more than one blade. All blades are attached to a single leaf stem. Where the leaf stem attaches to the twig there is a bud.

CONIFER

a cone-bearing tree.

CROWN

Branches, twigs, buds, leaves, flowers and fruit.

DECIDUOUS

shedding all leaves annually.

ENTIRE

a leaf margin with smooth, untoothed edges.

EVERGREEN

trees with needles or leaves that remain alive and on the tree through the winter and into the next growing season.

FASCICLE

A cluster of conifer leaves

FRUIT

The seed-bearing part of a tree

HABITAT

The place where a plant usually grows, e.g., a rocky, moist, well-drained, etc..

HARDWOOD

Term used to describe all broadleaved trees. These tree species are deciduous, retaining their leaves only one growing season. Despite the term, some "hardwoods" such as the aspens, have wood that is relatively soft.

HEARTWOOD

The area next to the pith, which is composed of deal cells and serves as support

INNER BARK (PHLOEM)

Conducts usable food from the leaves to the cambium to nourish it or to storage areas in the wood.

LEAF

Stalk and blade of hardwoods: needles and scales of conifers.

LEAF SCAR

the mark left on the twig where the leaf was previously attached.

LEAFLET

Smaller leaf units or leaflets which together form a compound leaf.

LOBES

projections that shape a leaf.

MARGIN

the edge of a leaf.

MEDULLARY RAYS

These rays radiate out from the center of the tree, and serve in lateral conduction and as food storage areas. They are most visible in a cross-sectional view of the tree trunk.

MIDRIB

the primary rib or central vein of a leaf.

OPPOSITE

2 or 3 leaves that are directly across from each other on the same twig.

OUTER BARK

The area of the tree trunk composed of dead cells. It insulates and protects inner tissues from disease infections and drying.

PALMATE

blades or lobes or veins of the leaf arranged like fingers on the palm of a hand.

PERSISTENT

deciduous leaf blades that remain on the tree for more than one year.

PETIOLE

the leafstalk that connects the blade(s) to the twig.

PHOTOSYNTHESIS

This is the process that occurs in the leaves. From energy produced by sunlight, the leaves combine carbon dioxide from the air and water from the soil to produce carbohydrates. Oxygen is released in the process. Carbohydrates plus fats and proteins are the plant foods necessary for growth and respiration of the tree.

PINNATE

blades or lobes or veins of the leaf arranged like the vanes of a feather.

PISTILLATE

The part of the leaf that contains female portions of flowers, or the pistils

PITH

The central, soft part of the stem.

ROOTS

Root hairs absorb water and mineral salts from the soil. Larger roots anchor the tree and store nitrogen and carbohydrates.

SAMARA

winged fruit.

SAPWOOD

The area on the outer side of the trunk, which contains the sap conducting tubes. Sapwood is usually lighter in color, but it darkens with age and becomes heartwood. Heartwood and sapwood together comprise the xylem.

SEED

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

SIMPLE LEAF

a single leaf blade with a bud at the base of the leaf stem.

SINUS

indentation between lobes on a leaf.

SOFTWOOD

Term used to describe all needle-leaved trees. These species are typically evergreen, retaining their leaves through two or more growing seasons. Larches, including tamarack, are exceptions, being deciduous "softwoods"

SPURS

stubby, often sharp twigs.

TEETH

notches on the outer edge of a leaf.

TREE

A woody plant, generally single-stemmed, that reaches a height of more 15 feet at maturity. A tree has three major parts: roots, trunk and the crown.

TRUNK

The main body of the tree.

The Encyclopedia of North American Trees is a great starter encyclopaedia covering 278 species of North American trees.

Thanks for taking time out to read the tree leaf identification blog