Pecans are valuable trees known for the tasty nuts they produce, with the nuts going into cakes, ice cream, candy and other dessert foods. The native range of the pecan tree (Carya illinoensis) is in the southern central portion of the United States, in states such as Texas, Oklahoma, Arkansas, Louisiana and Missouri. However, pecans are one of the most important of all cultivated plants in the nation and now grow on plantations throughout the Deep South, in states like Georgia and Florida. The pecan tree has leaves that you can recognize by several of their features.
Look at the compound nature of the leaves on a pecan tree. Compound leaves differ from simple leaves in that they have a composition of several individual leaflets arranged on a long stem called a rachis. Each rachis and the accompanying leaflets make up one leaf. Like the other members of the hickory family to which it belongs, the pecan features this type of compound leaf.
Measure the central rachis on the pecan tree's leaves. The rachis is from a foot in length to about 20 inches long, notes the "National Audubon Society Field Guide to Trees." Each separate rachis grows in an alternate pattern on the branches of the pecan tree, one at each node on the limbs rather than two or more growing opposite each other.
Count the leaflets, which attach by their short stalks to the rachis of the pecan tree leaf. There may be as few as nine, but there can also be as many as 17; there is typically an odd number of leaflets on the rachis. The leaflets grow opposite on the rachis from each other, with the exception of the single leaflet at the end of the rachis.
Note the size and the shape of the leaflets. The leaflets will be from 4 to 8 inches in length, 1 to 2 inches in width and have the same shape as the head of a spear. This lanceolate shape tapers to a long pointed end. The edges have fine toothlike serrations along their borders.
Observe the dark shade of greenish-yellow on the pecan leaflets and feel the undersides, which are usually hairy, while the upper surfaces are smooth. The foliage changes to mostly yellow in autumn before falling off and leaving the branches of the pecan bare.