Marrubium vulgare

Tracheophyta MagnoliopsidaLamiaceaeMarrubiumMarrubium vulgare

Ecology

A perennial herb, probably native only near the sea on open, exposed cliff-top grasslands and slopes overlying limestone and chalk, and on sandy banks and verges in Breckland. It is cultivated for tea and its medicinal properties, and is naturalised in rough and waste places; it also occurs as a wool-shoddy alien. Lowland.

Status

Native

World Distribution

Eurosiberian Southern-temperate element; widely naturalised outside its native range.

© G. Toone, IWNHAS

Broad Habitats

Calcareous grassland (includes lowland and montane types)

Light (Ellenberg): 9

Moisture (Ellenberg): 5

Reaction (Ellenberg): 7

Nitrogen (Ellenberg): 8

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 4.6

July Mean Temperature (Celsius): 16.1

Annual Precipitation (mm): 861

Height (cm): 60

Perennation - primary

Perennial

Life Form - primary

Hemicryptophyte

Woodiness

Herbaceous

Clonality - primary

Rhizome shortly creeping

Count of 10km squares in Great Britain: 46

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -2.02

JNCC Designations

NBNSYS0000004258

Scarce Atlas Account

Scarce Atlas Account: 

Marrubium vulgare L.

White horehound

Status: scarce

 

 

This is an aromatic herbaceous perennial of lowland broken ground and parched calcareous grasslands. The `native' coastal stations are open cliff-edge grasslands and coastal slopes subject to exposure to wind, soil creep, salt spray and insolation. These grasslands, in the presence of natural levels of herbivore grazing, are probably climax communities. M. vulgare tends to be found in relatively fertile, broken ground, or benefits from locally-intense rabbit or sheep dunging. The immediate associates may include Cirsium arvense, Malva sylvestris and Picris echioides. A wide range of notable species are found in association with M. vulgare in these habitats, including Euphorbia portlandica, Helianthemum canum, Orobanche artemisiae-campestris and Torilis nodosa.

Reproduction is by both seed and natural division of the herbaceous rootstock. Seed germinates freely in broken ground.

Long term trends in the distribution and abundance of this species are masked by the appearance and loss of naturalised colonies. The native coastal stations are under pressure from the elimination of natural grazing and the reluctance of the conservation managers to graze cliff tops and coastal slopes with domestic stock. The absence of any grazing is resulting in invasion by woody species or coarse herbs, which leave matted dead vegetation, resulting in the loss of open ground. Unlike annuals found in cliff top grasslands, M. vulgare is relatively tolerant of short term fluctuations in grazing pressure. It persists as a perennial even where bare ground is absent and plants cannot become established from seed. Where intensive grazing is present, the plant persists untouched by stock.

M. vulgare is found throughout Europe, except the far north. It also occurs in North Africa, the Middle East and further east through Asia. 

The true natural distribution of the species in Britain is unclear. M. vulgare has long been regarded as a valuable herb and as an attractive ornamental plant. The widespread cultivation of this species has resulted in numerous inland naturalised colonies. The species is generally accepted to be native in coastal exposures of limestones and some of the harder chalk formations. There is a strong likelihood that some inland stations, especially those on limestone screes, crags and parched grasslands, are also native.

 

 

C. Chatters

Atlas text references

Atlas (251c)
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Mabey R
1996.  Flora Britannica.
Meusel H, Jäger E, Rauschert S, Weinert E
1978.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols.
Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain.