The Difference Between Water Hickory & Pecan Tree Leaves

Similarities

• Important similarities exist between these two species of trees concerning their leaves. Both have compound leaves, meaning a main stalk called a rachis is the focal point of each leaf. This is a trait of all North American hickories. The rachis has leaflets connected to it to form one single leaf. These leaflets of the pecan hickory and water hickory do look somewhat alike at first glance, with the main resemblance being they have a slightly curved form, making them look like small sickles with pointy tips.

Size

• Almost everything about the pecan hickory leaf is larger than the comparable element of the water hickory, starting with the length of the rachis. While the water hickory rachis measures between 9 and 15 inches, the pecan hickory rachis is from 12 to 20 inches long. The individual leaflets are longer on the pecan hickory, growing to between 4 and 8 inches, while those of water hickory mature to be from 3 to 5 inches long. Both trees have leaflet widths in the range of 1 to 2 inches.

Leaflet Numbers

• Tell the difference between water hickory leaves and those of the pecan hickory by counting the number of leaflets on each individual leaf. On a water hickory, the number varies between five and 13 leaflets per rachis. According to the "National Audubon Society Field Guide to Trees: Eastern Region," a water hickory normally has at least nine leaflets on each leaf. On a pecan hickory rachis, look for there to be as few as nine to as many as 17 leaflets. If you discover a leaf with more than 13 leaflets, it cannot be that of a water hickory.

Other Differences

• Other, less obvious differences exist between the foliage of these nut trees. One is the color of the leaflets. Those of the pecan hickory are a shade of greenish-yellow on their top surfaces, but this color is pale on the undersides. Water hickory leaflets are dark green, with this color somewhat duller on the underside of the leaflet. Examination of the rachis of a water hickory leaf reveals it feels hairy and is a dark red color. Those of the pecan hickory are greenish and lack the hairs.