Northern bayberry (Morella pensylvanica, syn. Myrica pensylvanica) is native to eastern North America from Canada to Virginia and barely into North Carolina where it is rare. Scattered populations occur westward through Pennsylvania to Ohio. Southern bayberry (Morella or Myrica caroliniensis) is sometimes considered co-specific with M. pensylvanica because the two can hybridize. Northern bayberry also hybridizes with wax myrtle (Myricacerifera), a more southern species, where the two overlap on the east coast.

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 its typical, coastal 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.

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 thanks to their specialized digestive enzymes. 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. It is not native in Pennsylvania.)

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 surfaces and can be more fragrant. Northern bayberry's leaves are deciduous and drop in the fall, except at the southern end of its coastal range, where they persist longer, sometimes through the winter.

In Pennsylvania, northern bayberry is concentrated in many of the southeastern counties from Franklin to Pike, east to the Delaware River and south to the Mason-Dixon line. (Omitted exceptions are Cumberland, Perry, Northumberland, Lehigh and Monroe Counties.) Outliers are found in Columbia, Snyder, Centre, Westmoreland, Allegheny, Crawford and Erie Counties. "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).