Trees are among the most important natural organisms on the planet. In order for trees to thrive, they rely on their leaves for many matters, from wind resistance and driplines, to photosynthesis. Continue below to learn more about tree leaves by reviewing a glossary list of common tree leave terms.

Tree Leave Terms and Definitions

ALTERNATE – Alternate tree leaves are staggered along a twig rather than directly across from one another.
BLADE – Blades refer to the flat surface areas of broad tree leaf trees.
BRACT – Bracts are modified leaves that grows a flower.
BROADLEAF – Broadleaf trees are trees that have flat, thin, thins that typically shed once a year.
COMPOUND LEAF – Compound leaves are those that have more than one blade (see definition above).
CHLOROPHYLL – A green pigment in tree leaves (and cyanobacteria) that is in control of absorbing UV light in order to provide energy for photosynthesis (see definition below).
DECIDUOUS – Deciduous trees lose their tree leaves in the fall, enter dormancy in the winter, and blooms again in spring.
DRIPLINE – The perimeter around the canopy of a tree where the rains drips off of the leaves. See our blog, “How to Measure a Tree’s Critical Root Zone”, for help locating a tree’s drip line.
EVERGREEN – Evergreen trees do not lose their foliage, and remain “green” all year long.
LEAF SCAR – When a leaf detaches from a twig, a mark is left behind called a leaf scar.
LOBE – Tree leaf lobes are the protrusions that give a leaf its shape.
MARGIN – Leaf margin refers to a leaf’s edge. Accordingly, the term entire margin refers to leaves that have smooth, non-toothed edges (see definition below).
MIDRIB – The midrib is the primary vein of a leaf, also known as a rib.
OPPOSITE – Two or three tree leaves that grow along the same twig, but directly across from one another.
PALMATE – Tree leaves that have blades, lobes, or veins that are arranged in a way that is similar to fingers and hands.
PINNATE – Tree leaves that have blades, lobes, or veins that are arranged in a way that is similar to feathers.
PERSISTENT – Deciduous (see definitions above) tree leaves that fail to drop, and remain all year long.
PETIOLE – Petioles are essential the stem, or leafstalk, of a leaf that connects it to a twig.
SIMPLE LEAF – A leaf that has just one leaf blade with a bud at the base of the leafstalk.
SINUS – Tree leaves that have indentations between the lobes and blades (see definitions above).
TEETH – Leaf teeth are the notches on the outside edge of a leaf.