Henry’s Stone Oak: Lithocarpus henryi


by Tony Avent

 illustration by Ippy Patterson

Since Raleigh is known as the City of Oaks, most residents like to think they can identify oak trees, but when I show Henry’s oak to garden visitors, their jaws drop to an unnatural position. Then, after a head shake, they all repeat the same line: “That’s not an oak!”

Oaks are a fascinating group of trees belonging to the beech family (Fagaceae), which are often far different from the few species that most area residents know.

Common oaks in and around Raleigh include white oak, (Quercus alba), red oak (Quercus rubra), water oak (Quercus nigra), Southern red oak (Quercus falcata), willow oak (Quercus phellos), pin oak (Quercus palustris), and saw tooth oak (Quercus acutissima).

Long ago, plant taxonomists split oaks into three different groups, called genera. These include Quercus, which has 600 species; Cyclobalanopsis, which has 150 species; and the stone oaks of the genus Lithocarpus, which has 300 species. While Quercus has both deciduous and evergreen oaks, all lithocarpus and cyclobalanopsis oaks are evergreen.

The easiest way to tell a stone oak from a “regular oak” is by the flowers. We all recognize the flowers of our local Quercus oaks: The dangling, golden-brown, slim flower clusters that share their pollen with our noses and vehicles in spring, around the time of leaf emergence.

Stone oaks flower much later in the year, and do so with upright sprays of flowers.

I first met Lithocarpus henryi many years ago at Woodlanders Nursery in South Carolina, which has been the source of most of the Henry’s oaks planted throughout the country.

Lithocarpus henryi was born, however in South Central China, where the original plants still reside in forests at 5,000- to 7,000-foot elevations.

I planted my Henry’s oak in 1990, and in the subsequent 23 years, it has made a striking 25-foot tall specimen. The one-foot diameter trunk is dark grey, blotched with silver, and the limbs are laden with thick, immaculate, glossy, dark-green, lance-shaped, plastic-like, evergreen, eight-inch-long leaves. I’d grow Lithocarpus henryi for the foliage even if it didn’t bloom, but it also has amazingly beautiful flowers.

For us, Henry’s oak flowers twice yearly: The first time in mid-June, then again in mid-October. Its showy, upright, branched flower panicles are adorned with dozens of the tiny ivory white flowers. We’ve found the subsequent acorn set is – strangely – quite sparse in our climate.

You’ll find Henry’s oak planted occasionally around Raleigh, most notably in some of our city parks, thanks to retired city horticulturist Noel Weston.

As we embrace plant diversity in the same way we embrace human diversity, I hope you’ll consider adding this or one of the many other lesser-known oaks to the City of Oaks. In the meantime, consider a weekend excursion south to Aiken, S.C., to see one of the largest public oak collections in the country. Of course, if you’re one of those overly obsessive folks who want to grow them all, you can join the International Oak Society – a group of mad (in a good sense of the word) oak collectors.