Biological Flora of the British Isles: Serratula tinctoria

Abstract

Summary This account presents information on all aspects of the biology of Serratula tinctoria L. 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. Serratula tinctoria is a gynodioecious perennial forb of open or semi‐shaded habitats including grassland, heath, mire, open woodland and scrub and their ecotones. It is found throughout most of England and Wales but it is very rare in Scotland and absent from Ireland. Serratula tinctoria is found in Europe as far north as southern Sweden and Norway. It is absent from much of the Boreal biogeographical zone, including most of Fennoscandia and northern Poland, Russia and the Baltic States, and from the lowland Mediterranean zone. Serratula tinctoria occurs on soils overlying a wide variety of superficial deposits and sedimentary, metamorphic and igneous rocks, including ultramafic rocks. The pH range of these soils is wide, ranging from acidic to moderately alkaline but with nutrient status classed as oligotrophic, or more rarely mesotrophic. In mire or fen habitats, it occurs in topogenous or soligenous situations with a similar soil water pH range. It is able to tolerate a wide spectrum of soil water‐table conditions, ranging from very dry to flooded. Serratula tinctoria is pollinated by various insects of the orders Hymenoptera, Diptera and Lepidoptera, particularly bumblebees, hoverflies and butterflies. It produces phytoecdysteroids, which mimic a hormone that regulates insect development. The seed has a feathery pappus for wind dispersal and establishment is primarily from seed. However, it has strong dispersal limitation with slow migration rates into restored grasslands of 1 m year−1. The species has a short‐term persistent seed bank. Seedling recruitment is enhanced by disturbance that creates bare ground, increasing light flux and lower cover of bryophytes and litter, and reduced by higher nutrient availability and lack of management. Formerly the source of a yellow dye, S. tinctoria has declined in Britain since at least the late 19th Century primarily due to a combination of drainage, ploughing and agricultural improvement and, conversely, lack of management by cutting and grazing in its grassland, heath and mire habitats. There is evidence that the decline slowed or stabilised between the late‐1980s and the mid‐2000s, in part due to the positive impact of conservation via statutory protection on designated sites and wider measures delivered through agri‐environment schemes.