Common Three-seed Mercury is an annual native herbaceous plant in the spurge family (Euphorbiaceae) and occurs in all areas of NC. It is native to the central and eastern USA and into Canada. It can be found in various disturbed areas. The species name means "diamond-shaped" in reference to the leaves. It prefers sun to light shade and will grow in moist to dry clay, loam or rocky soils. It has a deep tap root, grows 1-2 feet tall and rarely branches This plant has tiny flowers with large lobed bracts in summer to fall and freely self-seeds. The sap of this plant is clear rather than milky as most spurges have, It can be weedy and is not recommended for home gardens. Birds will eat the seeds. Insects, Diseases, and Other Plant Problems: No significant problems. More information on Acalypha .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Shallow Rocky
Soil drainage
Good Drainage | Moist | Occasionally Dry
Growth rate
Rapid
Maintenance
High
Form & Appearance
Habit / form
Erect
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Lanceolate; Ovate
Leaf margin
Serrate
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
Yes
Leaf detail
Lanceolate to ovate simple alternate leaves with serrated margins, conspicuous pinnate venation and hairy petioles. 3.5" long and 1" wide. The leaves tend to congregate together near the top of the stems. In the fall leaves can be copper-purple hence the common name.
Fall color
Brown/Copper; Purple/Lavender
Flower form
Insignificant
Flower size
< 1 inch
Flower detail
Mid-summer through fall. A 5-9 lobed bract forms around the inflorecese in the axils of the leaves. There are both male and female flowers within the bract without petals or sepals.
Bloom time
Fall; Summer
Fruit type
Capsule
Fruit detail
3 lobes spherical capsule containing three seeds.
Stem color
Green
Stem detail
The central stem is usually unbranched with lines of fine white hairs or just hairy.
Wildlife & Ecology
Native status
Native
Origin
Eastern Canada, central and eastern U.S.A.
Distribution
AL , AR , CT , DC , DE , FL , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , NC , ND , NE , NH , NJ , NY , OH , OK , PA , RI , SC , TN , TX , VA , VT , WI , WV Canada: NB
Wildlife value
Seeds are eaten by birds
Food & Medicine
Harvest time
Fall
Fruit type
Capsule
Landscape Use
Landscape location
Naturalized Area
Garden tags
#native annual #native weed #NC native #self-seeding #disturbed areas #annual weed #full sun tolerant #bird friendly #high maintenance #weedy