If Adam had examined the leaves of that fruit tree, he might have known that Eve was handing him an apple. In Adam's case, ignorance was anything but bliss. If you want to know what kinds of fruit trees are growing on your property, you can be like Adam and wait until it is obvious, or you can figure it out by identifying the tree's foliage. Years ago, leaf identification required plucking a specimen and taking it to the library. Later, printed field guides made it possible to identify a leaf while in the field. Electronic technology provides other options for amateur dendrologists in identifying fruit trees.
Examine the leaf's colour, shape, size, arrangement and structure. Pay particular attention to the leaf shape and whether the leaf is "simple" (grows by itself) or "compound" (is part of a group or cluster). Apple trees have simple, oval-shaped leaves. Peach trees have long, lanceolate (lance-shaped) leaves.
Notice the venation, or vein pattern, of the leaf. Peach, apple and cherry trees have "pinnate" venation--paired veins extending from a central larger vein, or midrib. Palmate, or hand-shaped, venation is found in some fig leaves.
Photograph a single leaf or leaf cluster on the white card stock using a digital camera or your camera phone. Record the image on a card or send it to your e-mail account. Place the leaf sample into a sandwich bag.
Compare the digital leaf image and your sample to photographs and drawings in your printed field guide, or look it up on the internet. Use the search words "fruit tree leaf identification" or "identifying trees" to find resources for photographs of tree leaves.
Utilise credible online leaf identification manuals to guide you in your leaf analysis. Many universities have information on their agricultural and horticultural departments' websites.