Short to medium hairless, or slightly hairy plant. Stems branched from the base. Leaves oval to lanceolate, toothed and short stalked. Female flowers few, 3 to 4 mm in small axillary clusters. Fruit 2 to 3 mm, bristly. 

Mercurialis perennis

Annual plant (no rhizomes); stems often branched; stems and leaves glabrous or nearly so; different habitat to perennial dog's mercury, which is a shade-lover.

Photograph of plant in its habitat with details of leaves and stems

Disturbed and waste places, cultivated ground, particularly in allotments and gardens, rubbish tips, walls, and roadsides, thriving on light, nutrient-rich soils.

Flowering July to October.

Annual. Male and female flowers on separate plants.

Previously mainly recorded from southern and eastern England but believed to be spreading to other areas of Britain.

Near scarce but possibly increasing in Leicestershire and Rutland. In the Flora of Leicestershire (Primavesi and Evans 1988) it was found in 14 of the 617 tetrads.

In the current checklist (Jeeves, 2011) it is listed as Alien (archaeophyte); scarce

It was on the 2011 VC55 Rare Plant Register (Jeeves, 2011) but does not meet the criteria for the current RPR (Hall and Woodward, 2022)