Leaf Morphology Flashcards
What are the 3 common methods for Identification?
Keys, picture guides, and characterization
Characterization
Focus on distinct morphological features and unique characters of a plant
Classification
fitting plants into the basic 7 tier hierarchical system developed by Linnaeus
(broad) Kingdom>Phylum>Class>Order>Family>Genus>Species (narrow)
Blade
Broad, expanded part of a leaf
Petiole
Leaf stalk
Stipule
one of a pair of leaf-like appendages often found at the base of the petiole
Sissile Leaf
Leaf directly attached to the stem
Name the 3 common types of leaf arrangement
Alternate, Opposite, and Whorled
Alternate
one leaf borne per node; leaves spiral around twig (common)
Opposite
two leaves per node; leaves opposite each other on twig
Decussate
each adjacent pair of leaves is rotated about 90 degrees (specific type of opposite arrangement)
Whorled
3 or more leaves per node (also know as verticillate) (least common)
Dwarf Shoots
leaves crowded on lateral shoots. Less than an inch in length
Pin Shoots
leaves clusters on short shoots from main branch, but longer. An inch or longer in length (willow oak)
Simple Leaves
Undivided or uninterrupted leaf blade
Simple Leave Types
Lobed and Pinnatifid
Pinnatifid
Blade divided into lobes of which the sinus reaches nearly to the midrib.
Compound leaves
leaf blade divided into segments
What are the two leaf types
Simple and Compound
What are the parts of a compound leaf?
Leaflet, petiolule, and rachis
Leaflet
photosynthetic division of a compound leaf
Petiolule
stalk of a leaflet
Rachis
main axis of a compound leaf or inflorescence from which leaflets or flowers are borne
Pinnately compound
compound leaf with leaflets arranged on opposite sides of one elongated axis
