What Are Trees With Pinnately Compound Leaves?
What trees tend to dominate the hard wood forests of North America?
Hi, I'm Meghan Field, an air quality specialist in California with a background in Forestry and Natural Resources. I'm here today for About.com to answer the question: What are trees with pinnately compound leaves?Let's start with an explanation of the leaf itself. Pinnately compound leaves refer to a leaf that is comprised of two or more leaflets on a common stalk, where the veins within the leaf's lobes arise from several places along the central vein. You'll most often find these on walnut trees, ash trees, pecan trees, and hickory trees. Butternut and black walnut trees are the two most common types of walnut trees found in North America. Walnuts are deciduous, ranging from 30 to 130 feet tall.When examining their leaves, you'll notice that they have anywhere from five to 25 leaflets on a common stalk with an alternate leaf arrangement, and the blades are often lance-shaped. Ash trees are medium to large in size and mostly deciduous. When identifying an ash tree, look for opposite leaf arrangement on a common stalk, and leaflets that are similar to each other in size and shape. Grown in several regions throughout the U.S., pecan trees are deciduous and can grow up to 100 feet tall. You'll find 9-17 sickle-shaped blades on a common stalk, with alternate leaf arrangement.Finally, hickory trees tend to dominate the hard wood forests of North America. Their pinnately compound leaves usually have fewer than nine blades on a common stalk in an alternate arrangement, with three end leaflets much larger than the basal leaflets. Just a tip: While it's not a tree, a common woody plant that you should be aware of that has pinnately compound leaves is poison oak. With three leaves that come off the main vein, it's fairly easy to identify poison oak when you happen upon it. As the old rhyme goes: "Leaves of three, let them be."Thanks for watching. To learn more, visit us on the web at About.com.