Tree identification -- botany

Blade

The broad, flat portion of a leaf.

Petiole

The stalk that attaches the leaf blade to the stem/branch.

Midrib

The main central vein running through a leaf.

Veins

Branching structures within the leaf that transport water and nutrients.

Terminal bud

A bud located at the end/tip of a stem or branch.

Axillary bud

A bud found in the axil, where a leaf attaches to the stem.

Axil

The angle/junction between a leaf and the stem.

Node

Point on a stem where a leaf or bud attaches.

Internode

Section of stem between two nodes.

Pith

The central tissue inside a stem/branch.

Leaf scar

Mark left on a twig after a leaf falls off.

Bundle scar / vascular bundle scar

Small marks within a leaf scar where vascular tissue once connected the leaf to the stem.

Lenticel

Small pore/opening on a woody stem.

Bud scale

Protective scale covering a bud.

Lateral bud

Bud growing along the side of a stem rather than at its tip.

Alternate Arrangement

One leaf per node, alternating sides of the stem.

Opposite Arrangement

Two leaves per node, directly across from each other.

Whorled Arrangement

Three or more leaves per node, arranged around the stem

Pinnate venation

One main midrib with smaller veins branching off the sides.
Think: feather.

Palmate venation

Several major veins spread outward from one point.
Think: fingers spreading from your palm.

Parallel venation

Veins run alongside one another in roughly parallel lines

Dichotomous venation

Veins repeatedly fork into two branches.

Simple leaf

Has one continuous leaf blade attached to a petiole. It may be lobed, but it isn't divided into separate leaflets.

Compound leaf

One leaf is divided into multiple separate leaflets.

Leaflet

One of the individual blade-like pieces making up a compound leaf.

Rachis

The central axis of a compound leaf where the leaflets attach.

Petiolule

Small stalk attaching an individual leaflet to the rachis.

Terminal leaflet

Leaflet located at the end of a compound leaf's rachis.

Pinnately compound

Leaflets attach along the sides of a central rachis.

Odd-pinnately compound

Pinnately compound leaf with a terminal leaflet, giving it an odd number of leaflets.

Even-pinnately compound

Pinnately compound leaf without a single terminal leaflet, generally giving it an even number.

Palmately compound

All leaflets originate from approximately one central point, like fingers from a hand.

Doubly pinnate / bipinnately compound

The divisions of a pinnately compound leaf are themselves divided into leaflets.

Palmate Shape

Leaf is shaped/lobed so that the major divisions radiate outward like fingers from a hand.

Lobed Shape

Leaf margin has deep rounded or pointed projections/indentations.

Acute Shape

Leaf has a pointed tip.

Entire Shape

Leaf margin is smooth, with no teeth.

Truncate Shape

Part of the leaf appears cut off or squared across rather than tapering normally.

Serrate Shape

Leaf margin has saw-like teeth.

Angiosperm

Flowering plant.

Gymnosperm

Cone-producing seed plant.