Wood Flashcards
undifferentiated plant tissue; site of active cell division
Meristem
What is wood?
Accumulations of secondary xylem arising from a vascular cambium
cell division and elongation occurring in apical meristems of roots and shoots
Primary Growth
cell division occurring at lateral meristems
Secondary Growth
lateral meristem from which arises secondary vascular tissue
Vascular Cambium
vascular cambium cells that divide to form secondary xylem and secondary phloem
Fusiform Initials
vascular cambium cells that divide to form ray cells
Ray Initials
new cell ways are parallel to cambium; forms rays, phloem, etc
Periclinal Divisions
new cell walls are perpendicular to cambium; responsible for increasing girth of cambium
Anticlinal divisions
All material that is external to the xylem
Bark
tissue that replaces the epidermis
Periderm
secondary lateral meristem that produces phellum and phelloderm
Phellogen
layer of parenchyma tissue between phellogen and vascular cambium
Phelloderm
cork
Phellum
region of secondary xylem that actively conducts water
Sapwood
non-functional secondary xylem
Heartwood
lateral system of parenchyma cells
Ray
a polymer based on the cellobiose unit and is classified as a carbohydrate
Cellulose
polymers based on the phenylpropane unit and are classified as phenolics
Lignin
Hardwood comes from ________; Softwood comes from _______;
angiosperms (vessels); gymnosperms (tracheids)
wood type in which the diameter of early and late vessel members differ greatly
Ring-Porous Wood
wood type in which the vessels are uniform in size and distribution
Diffuse-Porous Wood
4 Primary Wood Characteristics
Color, Grain, Texture, Figure
What is grain?
direction of alignment of axial components
ex: straight, cross-grained, spiral, interlocked
What is texture?
Texture is dependent on size variations of xylem components
Coarse vs. Fine
What is figure?
pattern; dependent on type of cut
Plainsawed will typically bend
Quartersawed will typically not
How does a plant poop?
It will store waste products in leaves OR store it in its heartwood OR both i suppose
3 Areas of Primary Growth
Apical Meristem
Zone of Differentiation
Zone of Elongation
P.S. After cells elongate, they die
Alive vs. Dead
Phloem cells must be alive to transfer liquids! They use sieve plates and companion cells to uptake and transfer liquids. Xylem cells must be dead to function properly!!
Sap
Sugar Water, typically carried to leaves for new growth
