Bayberries (Morella sp.), Part 2

 

Song Sparrow atop a bayberry bush with summer leaves, June 26th, 
Assateague Island National Seashore, MD

Northern Bayberry (Morella pensylvanica, syn. Myrica pensylvanica) is native to eastern North America from Canada south along the coast, barely entering North Carolina where it is rare. Scattered outliers can be found westward to Ohio plus one limited population on the north shore of Lake Erie in Ontario, Canada. Southern Bayberry (Morella or Myrica caroliniensis) is sometimes considered co-specific with M. pensylvanica because the two can hybridize where their ranges overlap. From New Jersey south to its limit, Northern Bayberry also hybridizes with Wax Myrtle (Morella cerifera), an evergreen species which replaces it along the southeastern and Gulf coasts to Texas.

Bayberry is generally found growing in open, sandy soils with abundant sunshine. It does well as a "pioneer" species in this nutrient-poor environment by fixing its own atmospheric nitrogen with the help of Frankia spp. bacteria living in the shrub’s roots. This makes bayberry an ideal and beneficial candidate for the inter-dune environment where it enriches the soil and paves the way for other plants. Each plant can spread laterally up to 10 feet by rhizomatous growth. "Although typically considered a dune plant, Northern Bayberry also occurs inland thriving in fallow or abandoned agricultural land, along the borders of woodlands, pine barrens, marshes, swamps, and ponds" (Duncan and Duncan, 1987; Stalter, 1992).

Bayberry can grow to a height of 15 feet with dense branches and foliage making good cover for birds and other small animals plus browse for larger mammals. It is primarily dioecious with male and female flowers on separate plants. "Both male and female flowers are inconspicuous catkins; male flowers are yellowish green while female flowers lack both sepals and petals" [Brand, 2015] which is an indication of wind pollination rather than insect vectors. Mature fruits develop a bluish-gray, waxy coating with a high lipid content that makes them perfect bird food. Large flocks of migrating Tree Swallows will descend on the bushes and devour the fruits during fall migration.* Residual berries become cold-weather food for Yellow-rumped Warblers. The eastern subspecies is called the Myrtle Warbler in reference to the Wax Myrtle, a close relative of bayberry. (Wax Myrtle is a southern coastal plant from New Jersey to Texas.) Myrtle Warblers have special digestive enzymes that allow them to break down and absorb the wax. Most of the other bird species that eat the berries lack these enzymes, so much of the energy potential is wasted. The bayberry, however, still benefits from the bird's dispersal of the seeds.

Myrtle Warblers also eat Poison-ivy berries, as well as bayberry fruits, 

during autumn migration.

Bayberry's alternate leaves average two to three inches long and a half-inch wide. (Large leaves can reach four inches long and up to an inch wide.) The tips are bluntly pointed, sometimes with two or more tiny, lateral teeth, or simply rounded and smooth (entire).  The leaf bases taper like a wedge to a short stem (petiole). The undersides of the leaves have scent glands that are fragrant when crushed. By comparison, Wax Myrtle leaves have aromatic scent glands on both sides and can be more fragrant. Northern Bayberry's leaves are deciduous and drop in the fall. At the southern end of its coastal range, they persist longer and some may last through the winter.

Northern Bayberry plant form and leaves in autumn, 

Assateague Island National Seashore, MD

Northern Bayberry fruit detail in autumn, 

Assateague Island National Seashore, MD

If you have tips or tricks for separating and identifying the three main bayberry species, or anecdotes about these plants, please share them in a comment.

*For a photo and discussion of Tree Swallows and bayberries, 

please see the previous blog.

For more information on iNaturalist, see Northern Bayberry