Dog's Mercury - Mercurialis perennis

Description

Low to short rhizomatous hairy plant. Leaves lanceolate stalked, crowded towards the stem tops. Flowers greenish 4 to 5 mm, the female solitary or 2 to 3 together, the male in long tassel-like spikes.

Identification difficulty
Habitat

Shaded habitats, woods, hedge bottoms.

When to see it

February to April

Life History

Perennial

UK Status

Common throughout much of Britain, but rare in northern Scotland and in Ireland.

VC55 Status

Quite common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 259 of the 617 tetrads.

In the current checklist (Jeeves, 2011) it is listed as Native, locally abundant

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Species profile

Common names
Dog's Mercury
Species group:
flowering plant
Kingdom:
Plantae
Order:
Malpighiales
Family:
Euphorbiaceae
Records on NatureSpot:
360
First record:
27/05/2000 (MBNHS;Steve Woodward)
Last record:
12/04/2026 (Gray, Stephen)

Total records by month

% of records within its species group

10km squares with records

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Photo of the association

Melampsora populnea

Thie rust fungus Melampsora populnea causes galls on the alternate host plants Dog's Mercury and (rarely) Annual Mercury.  These are pale orange-yellow, white edged swellings up to 2 cm across, on leaf tips, distorted petioles and sometimes on stems.  The swellings carry spermogonia and orange aecia. The primary hosts, bearing uredinia and telia, are White Poplar, Aspen and the hybrid between the two, Grey Poplar.