Arborist Cert Flashcards
Angiosperm
Any non conifer or palm tree
Gymnosperm
Conifer trees
Meristem
Specialized growth initiation areas where new cells arise by cell division
Differentiation
Cells change their structure to assume a variety of different functions after cell division
Primary Growth
Growth from the roots and shoot tips resulting in increase of length and height
Secondary Growth
Growth that increases the thickness of stems, branches and roots
Apical Meristems
Small areas at the tips of roots and shoots
Buds
Where apical meristems are found
Cambium
Thin sheath of dividing cells located just under the bark. Produces cells that will be the vascular system for the tree
Xylem
Inner tissue created by the cambium.
Phloem
Outer layer of tissue created by the cambium.
Cork Cambium
Second lateral meristem that produces the outer tissues (periderm) and ultimately the bark. Palms lack this secondary growth.
Cellulose
Structural component of the primary cell wall. Plays a role in providing the architecture of different types of cells.
Lignin
A more rigid component of plant cells formed in the cell walls of the wood. Forms a matrix in which microfibrils (long chains of cellulose) are embedded; this forms a reinforcing structure similar to rebar in concrete. Allows trees to grow tall
4 Primary Functions of the Xylem
- Conduction of water and dissolved minerals (collectively known as sap
- Mechanical support for the tree
- Storage of carbohydrate (starch) reserves
- Defense against the spread of dysfunction, disease and decay
Tracheids
Elongated, close-ended, dead cells with pointed ends and thickened walls. They conduct water and provide mechanical support.
Parenchyma cells
Living cells interspersed among the other cells. Responsible for storing carbohydrates and defending against decay
Eudicotyledon (Eudicot)
Trees made up of vessel elements, fibers, and parenchyma cells. In some species tracheids may also be present.
Vessels
The primary conducting elements in angiosperms. Better at conducting water than tracheids.
Ring Porous
Trees that form wide vessels early in the growing season and narrow vessels later in the growing season. Includes elm, oak, and ash among others.
Diffuse Porous
Trees that produce uniform vessels throughout the growing season. Includes maple, planetree, linden among others.
Growth Rings
Visible in xylem. Result of cambium’s seasonal xylem production. Appear as rings because relative size and density of vascular tissues change throughout the growing season. Cells become smaller in diameter as the growing season progresses.
Earlywood
Cells produced early in the growing season
Latewood
Cells produced later in the growing season