L11: Wood and Labelling Practice Flashcards
planes
lines that cut/divide a specimen into different components
transverse plane
cross section perpendicular to the longitudinal axis
radial plane
along a radius
tangential plane
side cut of stem/trunk
heartwood
non-conductive wood that accumulates coloured metabolites/resins that function in storage and defense
Where is heartwood found in the trunk
interior to sapwood
sapwood
actively conducting portion of wood where the parenchyma cells are still alive
where is sapwood found in the trunk
interior to the bark
bark
all tissue outside the vascular cambium
outer bark
all the dead stuff; cork cells and residual epidermis
inner bark
all the living stuff; cork cambium, phelloderm, cortex, phloem
How do growth rings form
as a result of season slowing/cessation of vascular cambium
why are patterns within a growth ring variable
gradual reduction in diameter of tracheary elements from earlywood to latewood
when does earlywood form
at the beginning of a growth phase (ex: spring)
when does latewood form
after a growth phase
softwoods
generally needle-leaved evergreen trees (gymnosperms
softwood axial system
mostly tracheids that are non-porous
softwood radial system
ray parenchyma cells
examples of softwood
pine, spruce
What types of trees are hardwood
typically broadleaf deciduous trees (angiosperms)
hardwood axial system
tracheids and vessel elements that are porous
hardwood radial system
ray parenchyma cells that have more variety in size and shape
example of hardwood
maple, birch, oak
