Biological Flora of the British Isles: Stachys sylvatica L.

1. This account presents information on all aspects of the biology of Stachys sylvatica that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. 2. A rhizomatous perennial herb, with strong far-creeping stolons, Stachys sylvatica is a polymorphic native herb of open woodlands, hedgerows, banks of rivers and streams, widespread throughout most of the British Isles. 3. Stachys sylvatica occurs in light to moderate shade. It is suggested that the red/far red ratio is more critical than reduced irradiance in the plant's response to shading. 4. Stachys sylvatica occurs on moist or damp but not wet, weakly acid to weakly basic soils, and has been described as a nitrate indicator on base-rich soils. 5. Stachys sylvatica depends on seedlings established close to the parent plant for maintaining population density. Stolons are probably effective in extending the area of clones. 6. The hybrid between Stachys sylvatica and Stachys palustris, Stachys x ambigua, is most frequent in northern and western Britain, and occurs as an introduction outside the native range of Stachys sylvatica.