Allergy Information

Pollen allergenicity has not been studied extensively, but is rarely reported in North America.

Genus Details

This member of the spurge family is an herbaceous upright annual and a common weed found in cultivated fields. The plants are 4-24 inches tall with alternate lance-like leaves. Leaves resemble those of nettles and amaranths. The bracts (a special leaf-like structure surrounding the seed) are shaped like the wings on the feet of the god Mercury, hence the plant's common name: 3-seeded Mercury. Separate male and female flowers are located side-by-side on each plant, with the male flowers producing pollen which is typically airborne. Flowering occurs year-round in S. Florida, from June to autumn in S. states, and July to autumn in NC and the northern regions of the NE states in the U.S. Pollen is more plentiful in areas east of the Rocky Mountains.

Asthma Description

The pollen grains of Acalypha are oblate-spheroidal; the amb triangular to circular and 3-4 porate. The pores are ovoid with thickened margins and the opercula granular. The sexine is thin and slightly thickened at the pores.

The grains are small; 10-11 x 12 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