Galeopsis angustifolia
Ecology
An annual of arable land, waste places and open ground on calcareous substrates, including limestone pavements and scree; also found on eskers and on coastal sand and shingle. This late-flowering species often fails to set seed within winter-sown crops. 0-320 m (Derbys.).
Status
Trends
G. angustifolia was formerly a common cornfield weed in some areas (Druce, 1927), but the contraction in range shown in the 1962 Atlas has accelerated following a shift from spring- to winter-sown crops and cleaner crop husbandry. It is increasing on ground disturbed by gravel extraction in Ireland.
World Distribution
European Temperate element.
Broad Habitats
Light (Ellenberg): 8
Moisture (Ellenberg): 2
Reaction (Ellenberg): 8
Nitrogen (Ellenberg): 4
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 3.8
July Mean Temperature (Celsius): 15.8
Annual Precipitation (mm): 791
Height (cm): 50
Perennation - primary
Life Form - primary
Woodiness
Clonality - primary
Count of 10km squares in Great Britain: 616
Count of 10km squares in Ireland: 43
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -3.31
JNCC Designations
Scarce Atlas Account
Galeopsis angustifolia Ehrh. ex Hoffm.
Red hemp-nettle
Status: scarce
This lowland species is normally found in arable fields on calcareous soils. It is also known to occur on coastal sands and shingle in southern counties of England and Wales. It prefers well-drained, warm soils, faring best where competition is not too great. It is quite often associated with Euphorbia exigua, Fumaria densiflora, Kickxia elatine, K. spuria, Legousia hybrida, Lithospermum arvense, Papaver argemone and P. hybrida. On occasion it has such uncommon associates as Adonis annua, Torilis arvensis and Valerianella dentata.
This plant as a summer annual tends to germinate quite late in spring and consequently may fail to set seed before they are eradicated after the harvest. It is most frequently encountered in spring-sown crops and grows rapidly after harvest, setting much seed in stubbles if they are left in the late summer.
The decline of this species is apparent from the map. It competes poorly with dense, fully fertilised crops, and the increase in levels of nitrogen application and herbicide use, the switch from spring to winter sowing and the early ploughing of stubbles have probably contributed to its decline. Although there are records from 116 British 10 km squares from 1970 onwards, this declining species is classified as scarce as it has been recorded in only 61 British 10 km squares from 1980 onwards.
This species is found in western, central and southern Europe, eastwards to Poland and Bulgaria. It occurs as far north as southern Sweden, where it has been introduced.
A. Smith & P. J. Wilson
Atlas text references
Atlas (250a)
.
1988. The Irish Red Data Book. 1. Vascular Plants.
.
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
.
1978. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols.
.
1994. Scarce plants in Britain.
.
1962. Some notes on Galeopsis ladanum L. and G. angustifolia Ehrh. ex Hoffm. Watsonia. 5:143-149.