Starved wood-sedge  (Carex depauperata)

Starved wood-sedge is one of Europe's rarest sedges (4). It characteristically produces few flowers and has very large fruits (called utricles) (8). It grows in dense clumps (8) and has green or yellowish-green leaves (6), which are 2-4 mm wide (7), have shiny reddish sheaths (6), and stay green throughout winter (8). The leaves are fairly erect, and droop at the tips (8).

This species has only ever been recorded from 14 sites in Britain (8): in Kent, Dorset, Anglesey, Surrey, Somerset and Edinburgh (8). At present just two sites continue to support native populations of the species, one in Surrey, the other in Somerset (3). Two further sites have been the recipients of translocated populations (8). Elsewhere, the species has a wide distribution in Europe and Asia, with strongholds in Spain and France, although it is rare in many countries (8).

Starved wood-sedge inhabits dry, often calcareous brown-earth soils (8), and typically occurs in gaps and on tracks in broadleaved woodlands, and more rarely on rocky outcrops (3) and at the bases of hedgerows (8). It fares well in full-sunlight but can tolerate a level of shade (8).

This perennial species flowers in April and May, and the seeds are shed from October to March (3). It is unusual amongst British sedges as it produces very few large seeds (3). Plants usually begin to flower in the second or third year of life (8). The tall stems that support the inflorescences of flowers are thought to be an adaptation to disperse the seeds away from the parent plant (3). Large plants can produce up to 200 inflorescences when growing in good light (8). Seed production is good, however the means of seed dispersal is not known; it is thought that rodents and other seed-eaters may be important, and that after heavy rain the flow of water could occasionally help to spread the seeds (8).

Plants growing in cultivation are known to have lived for 25 years, although in the wild the longest life-span recorded is 13 years; most specimens, however, live for just 2- 5 years (8). This species is able to survive periods when the tree canopy closes, as the seeds can stay dormant in the soil for a considerable length of time, germinating when conditions become suitable once again (3). It is possible that the seeds may remain in a viable but dormant state for as long as 20 years (8).

The causes of the loss of this species from 10 sites are not known. A lack of suitable management resulting in an increase in shade, and forestry operations are thought to have been responsible at other sites (8). At present, this sedge is threatened by unsuitable management of woodlands, resulting in over-shading or an increase in competition from other plants. Over-grazing, damage by vehicles and landslips are also threats (8).

The remaining sites are managed in order to provide suitable conditions for the species to survive. Management to open up the canopy has been recommended on a five-year cycle (8); this may also encourage the species to return from the dormant seed bank (3). A population in Somerset occurs within a Site of Special Scientific Interest, and therefore benefits from a level of protection (3). Furthermore, Plantlife, the wild plant conservation charity, has included starved wood sedge in its 'Back from the Brink' programme (5), and carries out annual monitoring (8). Cultivated stocks exist, and seeds have been put into the Millennium Seed Bank at the Royal Botanic gardens, Kew (8).

For more on Plantlife, the wild plant conservation charity see:
http://www.plantlife.org.uk/
For more on this species see the book: New Atlas of the Flora of Britain and Ireland, by Preston, C. D., Pearman, D. A., Dines, T. D. (2002). Published by Oxford University Press, London.

Information jointly authenticated by Tim Rich of the National Museums and Galleries of Wales, and Plantlife.