Mentha pulegium

Tracheophyta MagnoliopsidaLamiaceaeMenthaMentha pulegium

Ecology

A short-lived perennial herb of seasonally inundated grassland overlying silt and clay. The majority of native populations are now confined to pools, runnels, ruts and poached areas on heavily grazed village greens, but habitats also include damp heathy pastures, lake shores and coastal grassland. Lowland.

Status

Native

World Distribution

European Southern-temperate element.

Broad Habitats

Light (Ellenberg): 8

Moisture (Ellenberg): 7

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 7

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 4.4

July Mean Temperature (Celsius): 15.9

Annual Precipitation (mm): 869

Life form information

Height (cm): 30

Perennation - primary

Perennial

Life Form - primary

Hemicryptophyte

Woodiness

Herbaceous

Clonality - primary

Rhizome far-creeping

Count of 10km squares in Great Britain: 242

Count of 10km squares in Ireland: 45

Count of 10km squares in the Channel Isles: 6

Atlas Change Index: -0.7

Distribution information

Plantatt Conservation Status

Vulnerable

JNCC Designations

NBNSYS0000004194

External Species Accounts

Scarce Atlas Account

Scarce Atlas Account: 

Mentha pulegium L.

Pennyroyal

Status: rare

WCA Schedule 8 species

 

This is a short-lived perennial herb of seasonally inundated grassland, usually appearing within and around ephemeral pools and runnels. The grasslands supporting M. pulegium are very short turf overlying clay and silt and are subjected to intense all year round grazing, trampling, dunging or disturbance by livestock or vehicles, causing poaching and ruts. This habitat is found within traditionally managed lowland village greens, settlement-edge lawns adjacent to open heath, and the verges of unmetalled trackways. Relic populations appear to persist in the presence of rutting and poaching in the absence of hard grazing. The ephemeral pools are typified by broken ground with grasses such as Agrostis spp. and the herbs Chamaemelum nobile, Gnaphalium uliginosum, Lythrum portula and Ranunculus flammula. The habitats supporting M. pulegium also contain a wide range of rare and scarce plants including Cicendia filiformis, Galium constrictum, Pilularia globulifera and Pulicaria vulgaris

A mature plant of M. pulegium consists of a central group of rooted stems giving rise to a mass of weakly rooting arching non-flowering stems. When subject to trampling, rutting or ‘mulching’ by dung, the stems readily root. As each fragment of M. pulegium is short-lived, this process needs to be continuous if the plant is to persist. If conditions are suitable, the plant may become the dominant species in the turf. M. pulegium flowers freely and sets seed but seedlings have rarely, if ever, been seen in the wild.

As traditional management of village greens has become very scarce in the lowlands, this species has declined. It is only in the New Forest, where a pastoral economy persists, that the plant is found in the abundance historically reported from commons throughout the lowlands. M. pulegium is just one of a suite of species associated with village greens which have declined (Bratton 1990; Hare 1990). Even within land owned by conservation agencies, it is important to achieve a change in perception to permit the survival of these superficially untidy habitats (Byfield 1991). Threats come from ornamenting greens with flowering trees, excavating seasonally wet areas to ‘save’ village ponds, and filling ruts in tracks with hard core. Although there are records from 20 British 10 km squares from 1970 onwards, this declining species is classified as rare as it has been recorded in only 15 British 10 km squares since 1980.

Widespread in Europe, north to Ireland and Poland, and also present in Macaronesia, North Africa and the Near East. It has declined elsewhere in Europe.

 

C. Chatters

PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.