The Oak Family

Part of the Native Plant Trail


Written and narrated by Ed Miller.

The Oak Family

New York has 14 species of Oaks that are considered native. Twelve are planted here. Missing is the Willow Oak, a state endangered species, and Blackjack Oak, a southern species also found on Long Island.

NY has one native specie of Beech, and one of Chestnut. The latter is the specie wiped out early in the 1900s by an introduced plant disease. The disease acts to girdle the mature tree, but the root often lives on and sends up new growth. The cycle repeats in 20-30 years. In the capital district, sprouted chestnut trees are quite common. We have one planted in this area. It will likely succumb when it reaches 3-4 inches in diameter. Hopefully it will re-sprout for the next generation’s enjoyment.

All of these species are important food producers for wildlife, and in simpler times, for primitive man. The family name, Fagaceae, refers to food. You may think the tannin in acorns would make then inedible, but early man learned how to grind the acorns and remove the soluble tannic acid. In the American Southwest, acorns were a particularly important part of our Native Americans’ diet. Bears, turkeys, and many other animals depend upon acorns and beechnuts. Bears will even climb to the highest branches of trees to gather and eat them before they ripen fully and fall to the forest floor.

Beech nuts are quite tasty, although somewhat difficult to extract from the husk. Years ago, I wondered if I could peel them fast enough to keep from starving. Bears eat them husks, leaves, twigs, and all, and leave the separation to their digestive process.

In New York, the 14 species of Oaks can be divided into Red and White Oak groups. Red Oak (which includes Black, Scarlet, Pin, and Bear Oak) leaves have lobes with sharply pointed tips, while the lobes of White Oak leaves have rounded tips. The acorns of Red Oaks take two years to mature and have a high tannin content. The several white oak species all mature their fruit in one year and their acorns are quite palatable. Squirrels eat them as they find them, whereas they generally bury the red oak acorns for winter food. The white oaks survive by having acorns that germinate quickly. The Red Oaks entice the squirrels to gather and bury their acorns by concentrating the tannin in the vital portion and reducing the tannin content in the portion of the acorn that serves only to provide food for the sprouting tree. Under favorably conditions, the sprout will grow from half eaten acorns.

Across the road the Fred Lape trail passes through the renowned oak collection that has brought fame to the arboretum. It has mature trees, both native species and species or hybrids from around the world.

Why do we need two collections? Well, they complement each other. The collection in front of you consists of young trees with low branches that easily permit one to examine the leaves or winter buds with a hand lens to see features that help identify the species. They are all planted close together so that one can go back and forth between similar species and observe the differences. With a good search image, you can confidently and accurately identify oak species when seen in other locations.

Fred Lape’s collection has the advantage that the trees have mature bark and acorns. Both characteristics helpful for identification. People interested in planting landscape oaks on their property will do well to observe mature trees for their characteristic shapes.