STEMS

Woody Twig

An axis with leaves attached, arranged in various ways around the stem.

Nodes

The area of a stem where a leaf or leaves are attached; the region between nodes is called an internode.

Petiole

The structure that connects the stem of the plant to the blade of the leaf.

Axil

The angle between the upper side of a leaf or stem and the supporting stem or branch.

Axillary Bud

A structure that forms in the axil of a leaf.

Leaf Scar

The mark left on a twig where a leaf has fallen.

Stipules

Paired, often leaflike appendages that may remain throughout the life of the leaf.

Apical Meristem

The meristem at the tip of each stem that contributes to the increase in stem length.

Protoderm

The thin outer layer of the meristem that gives rise to the epidermis.

Procambium

The tissue that appears interior to the protoderm and produces primary xylem and phloem.

Ground Meristem

Produces parenchyma tissue, with the pith located in the center of the stem.

Pith

A tissue composed of large cells that break down shortly after formation.

Cortex

A tissue that may become more extensive than the pith but is eventually replaced by new tissue.

Vascular Cambium

A layer of cells that divides indefinitely, producing secondary xylem and phloem.

Lenticels

Structures that develop beneath the stomata for gas exchange.

Stele

All tissues inside a distinct physiological barrier, excluding the endodermis.

Protostele

A solid core of conducting tissues where phloem surrounds xylem.

Cotyledons

Seed leaves attached to embryonic stems in flowering plants.

Dicotyledons

Flowering plants with two cotyledons.

Monocotyledons

Flowering plants with a single cotyledon.

Herbaceous Dicotyledonous Stems

Nonwoody stems of plants that complete their life cycle in one growing season.

Monocotyledonous Stems

Stems of monocots that are sources of commercially important fibers.

Cambium

A tissue that produces conducting tissues and parenchyma cells between vascular bundles.

Seasonal Wood Production

The process by which trees produce wood in spring and summer.

Annual Rings

The growth of xylem in one year, visible as rings in the wood.

Increment Borer

A tool used to determine a tree's age without cutting it down.

Rhizomes

Horizontal stems that grow below ground and produce adventitious roots.

Runners

Horizontal stems that grow above ground along the surface.

Stolons

Similar to runners but grow beneath the surface in various directions.

Tubers

Thickened parts of plants that store nutrients and support new growth.

Bulbs

Large buds made of fleshy leaves with a small stem at the bottom.

Corms

Structures resembling bulbs but primarily made of stem tissue.

Cladophylls

Stems that resemble leaves in function and appearance, with determinate growth.

Wood

A porous and fibrous structural tissue found in the stems and roots of woody plants.

Density

The measure of moisture retention, shrinkage, swelling, and mechanical properties of wood.

Durability

The ability of wood to withstand decay from organisms and insects.

Plainsawing

Lumber cut tangent to annual rings, typically at an angle of 0 to 45 degrees.

Quartersawing

Wood cut radially to the annual growth rings, typically at an angle of 45 to 90 degrees.

Knots

Lost branches covered by new wood rings, found in old logs.

Hemlock

A soft, light wood used for paper pulp and structural lumber.

Red Spruce

A softwood favored for violin sounding boards due to its resonant qualities.

White Oak

A durable hardwood used for barrels and various construction purposes.

White Pine

A softwood widely used in home construction and various products.

Hard Maple

A hardwood known for its resistance to abrasion, used in bowling pins and flooring.

Black Walnut

A hardwood prized for fine furniture and interior paneling due to its beauty and durability.