Allergy Information

All species are wind-pollinated and shed large amounts of pollen. Pollen has moderate to severe allergenicity. The southern wax myrtle is a significant cause of pollinosis, as well as the other species in North America where they are common.

Genus Details

6 of the 40 species of wax myrtles, or bayberries, are native to North America. The widely distributed family of aromatic, resinous shrubs and small trees are found in the coastal areas of California and states along the Atlantic Ocean and the Gulf of Mexico. Shrubs grow 4-9 feet tall and trees reach 36 feet in height. Sweet gale (M. gale) is found in colder regions of North America in moist peaty locations. The semi-evergreen bayberry (M. pennsylvanica & M. cerifera), native from Newfoundland to Maryland, has the waxy berries used to make bayberry candles. Male and female flowers are located on catkin-like spikes on separate plants or on the same plant, depending on the species. Only female flowers bear the single-seeded, waxy gray or purple fruits. All species are wind-pollinated and shed large amounts of pollen. Wax myrtle species flower from April to July in the northeast US, February-April in southeast, March-April in the southwest, and April-June in the northwest states.

Pollen Description

The pollen grains are suboblate; the amb rounded triangular with convex sides and 3-4 porate. The sexine is tectate, granular or minutely scabrate. The intine is thickened beneath the pores, forming an oncus.

The grains are 20-24 x 25-30 micrometers.

Genus Distribution

The shaded areas on the map indicates where the genus has been observed in the United States.

- Native, observed in a county 

- Introduced, observed in a county 

- Rarely observed