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Hophornbeam copperleaf
Acalypha ostryifolia L.


Hophornbeam copperleaf is a summer annual species and a member of the Euphorbiaceae (spurge) plant family. Many members of this family have a milky sap that exudes from the plant when injured, but hophornbeam copperleaf does not. This plant is native to the United States and can be found in fields, gardens, and wasteland areas stretching from New Jersey to Kansas and south to Florida and Texas. It may also be referred to as three-seeded mercury.


Hophornbeam copperleaf has round, pubescent cotyledons and true leaves with short hairs and serrated margins. Leaves are simple and alternate. A red coloration may be noticeable where the main leaf veins intersect the petiole. Plants can grow to be approximately 75-100 cm tall.

hophornbeam copperleaf seedling
Figure 1. Hophornbeam copperleaf seedling

Red coloration near petiole
Figure 2. Red coloration near petiole

Hophornbeam copperleaf is commonly misidentified as prickly sida (Sida spinosa). Prickly sida, however, has coarser larger leaf serrations and stipules (spines) in the leaf axils.

Hophornbeam copperleaf is monoecious (male and female flowers on the same plant). The male flowers are produced on axillary spikes, while the female flowers are produced on a long terminal spike. Capsules will split open when mature to release the seed. Previous research has reported that hophornbeam copperleaf produced 12,500 seeds when grown without competition, but seed production was greatly reduced (1000 seeds) when grown in competition with soybean. Seeds are about 0.2 cm in diameter, shaped like a raindrop, and have a wrinkled appearance.

Emergence of hophornbeam copperleaf begins in late May or early June, and may continue after each rainfall event throughout much of the growing season. Germination appears to be based on temperature which may explain the late flushes that occur.


The late- season emergence pattern allows hophornbeam copperleaf to escape many control measures. Dinitroaniline (DNA) herbicides such as Prowl and Treflan offer no control, while many acetolactate synthase- (ALS) inhibiting herbicides provide inconsistent control.

Control in soybean can be attained by the use of a soil-applied herbicide containing sulfentrazone, flumioxazin, metribuzin, or cloransulam. These soil-applied herbicides should be applied no earlier than two weeks before planting. Postemergence soybean herbicides containing aciflurofen, lactofen, fomesafen, or glyphosate provide good control of hophornbeam copperleaf. These herbicides should be applied before plants reach 10-15 cm in height for optimum control.

Hophornbeam copperleaf seeds Figure 3. Seed

A study at Oklahoma State University in 1971 found atrazine to be effective in controlling hophornbeam copperleaf. However, current application timing and rate restrictions may not allow atrazine to keep this weed in check. Mesotrione and pyridate in combination with atrazine provide adequate control of hophornbeam copperleaf when applied before plants reach 5 cm in height. Cultivation would also be beneficial.

Shade provided by a crop canopy can help suppress growth of hophornbeam copperleaf. Uniform crop stands and narrow row spacings decrease the amount of sunlight available to hophornbeam copperleaf. Producers should be aware that as the crop begins to mature and more sunlight reaches the soil surface, additional emergence of hophornbeam copperleaf may occur.

More resources:

ID poster

Corn and Soybean Classic Article

Images in Photo Gallery

PMCDB Article May 11, 2001

Figure 4. Mature hophornbeam copperleaf plants

Dawn E. Nordby (


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College of Agricultural, Consumer and Environmental Sciences
Crop Sciences| University of Illinois
University of Illinois Extension

Department of Crop Sciences