A nice generic image of a leafy green tree,
and a similar one with it's branches showing.
Simple cartoon one with circles representing the greenery.
Very colorful leaves on this Autumn tree and scattered on the ground around it.
Another beautiful Fall scene with leaves blowing in the Autumn winds.
A simple picture of a fruit tree.
Animated image of a fruit tree going through the seasonal changes.
A generic, leafy green tree.
Maple leaf fallen during the Autumn.
A little pile of maples leaves in the many colors of autumn.
A stylized pine tree with nice highlights.
A small collection of colorful autumn leaves.
This image of autumn leaves is a seamless background tile and is available as both a png and scalable vector graphic.
Here's the same image as the last one but a bit lighter so it can work well behind text.
A small breeze blowing a leave off the pile of a freshly raked pile of leaves.
A snow covered tree in the winter.