A blade of grass, a pine needle, a fern
frond, and a maple leaf are all leaves. Most leaves need light, air, and
water. Leaves contain green cells to make food for the entire plant.
![](../autumn/images/leavebar.gif)
Leaves look very different however.
Every plant has its own distinctive kind of leaf. Leaves help us identify
plants like fingerprints identify people.
![](../autumn/images/leavebar.gif)
Needle like leaves can be divided into two
groups. Needles can be attached singly to a stem. Other needle like
leaves have needles attached in bunches of two, three, or four.
![](../autumn/images/leavebar.gif)
Almost all other leaves can be grouped into
broad leaves. Broad leaves can be further classified by their pattern of
veins.
![](../autumn/images/leavebar.gif)
In palms, grasses, and other plants, the
veins run parallel to one another from the petiole to blade tip.
![](../autumn/images/leavebar.gif)
The branched or webbed group can be
classified into two groups--pinnate (featherlike) or palmate (fanlike).
![](../autumn/images/leavebar.gif)
In the pinnate group, the veins branch out
from the midrib like barbs of a feather.
![](../autumn/images/leavebar.gif)
The veins in a palmate leaf fan out from the
petiole and form a network of smaller veins through the leaf.
![](../autumn/images/next.gif)
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