Leaves Flashcards
abcission
he natural detachment of parts of a plant, typically dead leaves and ripe fruit.
blade
a leaf’s flat portion
netted venation
Smaller and smaller veins branch off from the larger veins to form a net
compound leaf
has a blade divided into two or more leaflets; divided into pinnately compound & palmately compound
palisade mesophyll
contains columnar cells stacked closely together and is the main site for photosynthesis; may have more layers in direct sunlight.
petiole
the stalk attaching the blade to a stem
parallel venation
veins running parallel towards each through the entire leaf
simple leaf
has a single blade
spongy mesophyll
contains the cells arranged loosely and irregulary and functions primarily in gas diffusion
mesophyll
composed mostly of chloroplast-containing parenchyma cells; two sub layers
stoma
any of the minute pores in the epidermis of the leaf or stem of a plant, forming a slit of variable width that allows movement of gases in and out of the intercellular spaces.
guard cell
have chloroplasts and associated with subsidiary cells; change in the shape of gaurd cells opens and closes the stoma
subsidary cell
A plant epidermal cell that is located next to a guard cell in the stoma of a leaf and differs in structure from other epidermal cells.
trichome
hairlike structures; reduce water loss from leaf surface; may secrete stinging irritants; may excrete excess salts
vascular bundle sheath
contains one or more layers of parenchyma or sclerenchyma cells; may extend towards both upper and lower epidermis ; form extensions
