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three seeded mercury weed

Well, you may have to learn to like Acalypha phleoides (shrubby copperleaf), or be more aggressive. It is native to this part of the state, and therefore very adapted to the rainfall, climate and soil. Since it is perennial, just pulling it off the root is not going to stop it from coming back up, as you have already pointed out. You can't spray it with herbicide, as it would kill all the other dicots or broad-leaved plants (like the straggler daisy) that you already have. If you buy a spray that is for monocots, or grasses, it won't bother the three-seeded mercury, but it could kill some native grasses that you have been cultivating.

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Monday – November 09, 2009

Identification of plant resembling garlic mustard, but with purple flowers
May 18, 2012 – While searching for the invasive garlic mustard I am finding a very similar looking plant (triangular, alternate, toothed leaves; four petals, same habitat of shaded roadside and interior woods) excep.
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The first thing to do is make sure it never has an opportunity to go to seed. Even though it is a perennial that can come up from the roots, it will also propagate itself by the seeds on those tall bracts. This might be a time to break your rule about never mowing; if you mow it before it can seed, and keep mowing it as it sends up more bracts to try to seed again, you might just wear out the food stored in the roots. Doing this for several weeks when the plant is trying to bloom, and thus set seed, could greatly alleviate your problem.

From our Native Plant Image Gallery:

Three-seeded Acalypha virginicacan be a somewhat aggressive summer annual weed. Cultural weed control methods—including proper lawn-mowing and watering habits—will not completely remove Three-seeded Mercury and should be used only as a supplement to professionally applied broadleaf weed killers.

◆Guarantee applies to full plan customers only. ✦Purchase of full lawn plan required for Healthy Lawn Analysis, which is performed at the first visit.

Three-seeded Mercury is a summer annual broadleaf weed that is also known as Virginia Copperleaf, Wax Balls, Copperleaf, Virginia Mercury and Mercury-weed. Its scientific name is Acalypha virginica.


Three-seeded Mercury can be identified by its vertically growing, branched stems that are hairy to sparsely hairy. The leaves are glossy and sparsely haired, developing a distinct copper pigmentation. In many areas, the leaves of this broadleaf weed soon become damaged by insect feeding. Three-seeded Mercury has a shallow taproot with a secondary fibrous root system. Blooming from July through October, Three-seeded Mercury features a spike of small, staminate flowers that lack petals. Reproduction occurs by seeds, and cross-pollination is by wind.

✢ Special price is for first tree and shrub application only and for new tree and shrub residential customers only. The special price applies to installed plant material and shrubs and excludes mature, native and specialty trees such as fruit or certain ornamentals. Application includes up to 5 trees, no more than 25 ft. in height. For the regular tree and shrub application price, please call for an estimate. Not to be combined with or used in conjunction with any other offer or discount for the same service. Consumer responsible for all sales tax.

This broadleaf weed does not appear to prefer any particular habitat and can be found in most disturbed areas, woodlands, thickets, prairies, meadows, abandoned fields, thin lawns, flower gardens and in areas along railroads and roadsides. Three-seeded Mercury can be found throughout much of the eastern and midwestern United States.

★Requires purchase of annual plan. Special price of 50% off is for first application only, for new residential EasyPay or PrePay customers only, and applies to lawns more than 5,000 square feet. For lawns less than 5,000 square feet or for the regular lawn application price for a lawn of any size, please call for estimate. Lawns less than 5,000 square feet may qualify for a first application only price of $29.95. Valid at participating TruGreen locations. Availability of services may vary by geography. Not to be combined with or used in conjunction with any other offer or discount.

Stems & Roots: Stems erect, 7.5-100cm (3-40in.) high, simple or branched, slightly hairy; leaves green to bronze-green, 1-9cm (2/5-3½in.) long, lance- to rhombic-ovate on petioles that are 1/3 the length to almost as long as the leaf blade; margins with irregular, rounded teeth.

Habitat: Three-seeded mercury occurs in dry or moist soil in open woods, fields, waste places, ditches and roadsides throughout south-central Ontario.

General Description: Annual, reproducing only by seed.

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Photos and Pictures

Similar Species: It resembles young plants of Redroot pigweed but is distinguished by its flowers borne in axillary clusters with bracts having 5-9 lobes and its leaves occasionally a bronze-green colour.

Three-seeded mercury.
A. Plant. B. Portion of fruiting stem showing 1 three-seeded fruit developing from 1 of 4 flowers in a leaf axil.

Flowers & Fruit: Flowers in greenish clusters in axils of leaves, each cluster composed of one or more palmately cleft bracts with 5 to 9 lobes, one or more stalked male spikes 4-15mm (1/6-2/5in.) long and one or more shorter female flowers; seedpods deeply 3-lobed (similar to those of Leafy spurge) and containing 3 seeds; seeds tan coloured, 1.6-1.8mm (1/15in.) long. Flowers from July to September.