Galeopsis angustifolia

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