Chapter One Flashcards
What is the cambium?
Layer between bark and wood that is responsible for tree growth and developed rings.
Rays
Group of horizontal cells that extend radially outwards from the pith.
Provides sap upwards towards the tree as well as store food.
Growth rings
Visible rings produced by the division of the cambrium during the annual cycles. (Growing & Dormant Season)
What is the function of a trees sap?
Through the process of photosynthesis, gets created gets carried down from the leaves to build new cells in the cambrium
Seasonal characteristics of cambrium
Growing Season, very fragile and bark is easily peels
Dormant season, stiffens and becomes less vulnerable to damage
Eaelywood
Visible contrast in first formed layer of wood
Latewood
All wood after the early wood the signifies growth during a season.
Grain
Direction of longitudinal cells in a tree.
Sapwood
Wood portion of the stem that carries sap upwards in tree (in twigs & small saplings)
(Prosenchyma cells are active and parenchyma cells store food)
Heartwood
After tree develops, it’s the whole trunk isn’t needed to conduct sap for leaf requirements and this turns into heartwood.
(Prosenchyma cells cease to conduct sap, parenchyma cells die)
Heartwood extracavities
Extractives cells in wood walls that develop that help protect wood from attacks. Immune system. Reason why wood gets its darker color.
Gymnosperms
Naked/exposed seeded trends
Usually softwoods
Excument (long and straight stem with subordinate lateral branches)
Pine, spruce, fir, hemlock, cedar
Angiosperms
Trees with covered seeds
Usually hardwoods
Branches and rebranches off of main stem
Spermatophytes
Seeded plants
Specific Gravity
Ratio of density of wood to a standard density of water
Higher density, more shrinkage
Good reference for strength
