FRST 200 Leaves

Leaves

Compound Leaf

Leaf structure consisting of several leaflets attached to a rachis or central point by a petiolule

Pinnately Compound

Compound leaf where leaflets originate from either side of a rachis

Odd Pinnately Compound

Compound leaves with a single terminal leaflet

Even Pinnately Compound

Compound leaf with two terminal leaflets

Palmately Compound

Compound leaf where all leaflets radiate from the same point at the tip of the petiole

Palmately Lobed

Leaf structure where the lobes appear to originate from the center of a leaf

Pinnately Lobed

Leaf structure where lobes extend from a central line extending from the base of the leaf

Opposite Leaf Attachment

When teach leaves attach to the same node on a stem opposite each other

Alternate Leaf Attachment

When only one leaf is attached to each node

Whorled Leaf Attachment

When 3 or more Leaves attach to the same node, surrounding the stem

Petiole

The structure attaching a leaf to the stem

Sinuses

The part of a leaf which dips between two lobes

Lobes

A rounded or pointed segment of a leaf which is separated from other lobes by a sinus which does not reach the midrib of the leaf

Leaf Venation

The arrangement of veins on a leaf

Palmate Venation

Several veins of roughly the same size extend from the base of the leaf

Pinnate Venation

There is one large central vein which extends from the base of the leaf, also called a midrib

Leaf Margin

The edge of a leaf/leaflet

Serrate Margin

Margin with serrations

Double Serrate Margin

Margin with serrations on serrations

Entire Margin

One solid, smooth margin

Sinuate Margin

Strongly wavy edge with shallow, rounded, indentations or curves

Cordate Leaf Shape

When the leaf base points back in towards the tip (makes a heart shape)

Ovate Leaf Shape

Oval shape with tapers into a point at the tip

Base is wider than the tip

Lanceolate Leaf Shape

Thinner leaf shape with an oblique/uneven base

Obovate Leaf Shape

Opposite of an ovate leaf shape, tapered base and rounded tip

Cuneate Leaf Base

When the base tapers off instead of rounding or folding back in

Truncate Leaf Base

When the leaf base attaches squarely to the petiole

Rounded Leaf Base

When the base is rounded into the petiole, somewhere between truncate and cuneate.