Red female hazelnut flowers and yellow male flowers (catkins).

It may seem like March is a bleak wasteland as we wait for signs of spring, but if you pay close attention, you may discover that more is happening in the plant world than you thought! In fact, two of our common native shrub species are popping into flower: beaked hazelnut (Corylus cornuta), and American hazelnut (Corylus americana).

Why bloom so early in the spring—long before most insects even emerge? Because not all flowers are insect pollinated. Many trees and shrubs practice anemophily, which means that they cast their pollen far and wide, into the breeze. Instead of the pollen grains being carried directly to female flowers by an insect or bird, it’s all up to air currents. So blooming when the branches are bare and there is no foliage to get in the way suits these trees just fine. Nantucket’s gusty winds are perfect to spread the love.

The red stigmas of beaked hazelnut’s female flowers begin to emerge from the buds in late February or March. Photo: K.A. Omand

Female flower buds on hazelnut twigs are larger than the leaf buds now on beaked hazelnut as they swell in preparation for opening. You can see a tiny bit of the ruby red stigmas just beginning to peek out between the bud scales.

The tiny ruby colored sea anemones on the twigs of hazelnut give one of the first clues that the spring flower show is beginning. The red stigmas are sticky and will catch the pollen blowing on the wind. Meanwhile, the male catkins have been elongating and soon the tiny flowers that make up these catkins will begin to bloom. As the tightly packed male flowers open, the catkin becomes more flexible and the wind can easily make it wiggle, sending golden pollen into the air.

Months from now, the fertilized female flowers will develop into clusters of the characteristic husk-covered hazelnut fruits. Beaked hazelnut (shaped like the head of a bird with a long beak) and American hazelnut (shaped like frilled deep-sea clams) are a common sight in late summer and early fall, but quickly get snapped up by birds and squirrels.

Beaked hazelnuts with the nut contained in the round base and an elongated curving “beak.” Photo: K.A. Omand
American hazelnut has nuts enclosed in frilly, clam shell-shaped bracts. Photo: K.A. Omand

Identifying Hazelnuts

Look for hazelnuts by seeking out shrublands and trails in forests. The catkins on the light brown branches of this medium height shrub will clue you in. There are other species on Nantucket with catkins–grey birch and sweetfern, for example–but look for shrubs with many stems coming from the ground, a warm light brown color and 2-8′ tall. Sometimes a lingering husk with nuts will be found in winter or late spring that will help you easily determine which species of hazelnut you’re examining.

If not, a hand lens will give you a closer look at the twigs to figure it out. American hazelnut has twigs that are hairy near the buds and catkins. If the twigs are hairless, then it is most likely a beaked hazelnut. Comparing mainland American hazelnuts to ones here on Nantucket, the Nantucket plants seem to be much less obviously hairy, which just goes to show how plants can vary across their range and in different habitats, but when I learned these shrubs, I associated the reddish hairs and stipitate glands on the nut husks with the species name, by remembering the red color as symbolic of America’s red, white, and blue. Here on Nantucket, the plants seem to have inconspicuous hairs and they are tan rather than reddish.

The two hazelnut species can grow side by side and their habitat requirements overlap, although one species is often dominant in a particular area of the island. Hazelnuts are a great shrub to add to your yard, as they are happy in part shade and even on well drained soils. They spread well but are easier to manage than many woody shrubs as they are less aggressive in growth form and easy to cut back. A great option for woodland gardens and to screen for privacy with a few other taller shrubs.

Interested in learning more about identifying trees and shrubs in winter condition? You’re in luck! This month I will be doing a Winter ID walk on Friday March 25th at Squam Farm, where you can join to learn how to identify some of our common species in winter condition. Check out the event and sign up online!