A perennial herb of dry, base-rich, free-draining soils. At its two extant sites in England it grows in semi-shade on laneside banks at the edge of deciduous woodland; in Ireland it grows in a partially shaded, wooded limestone area. It cannot tolerate deep shade. Lowland.
Woodland removal or lack of woodland management probably account for the decline of this species in Britain. It responds well to coppicing and periodic disturbance. One English site has been augmented with re-introductions. The species has been recently added to the Scottish flora as a result of the discovery of old herbarium specimens (Rich et al., 2000).
Submediterranean-Subatlantic element; also in C. Asia.
Light (Ellenberg): 5
Moisture (Ellenberg): 4
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 4
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 4.1
July Mean Temperature (Celsius): 15.8
Annual Precipitation (mm): 823
Count of 10km squares in Great Britain: 9
Count of 10km squares in Ireland: 1
Count of 10km squares in the Channel Isles: 0
RDB Species Accounts
Carex depauperata Curtis ex With. (Cyperaceae)
Starved sedge, Hesgen Lom
Status in Britain: CRITICALLY ENDANGERED. WCA Schedule 8.
Status in Europe: Not threatened. Endemic.
C. depauperata is a plant of dry basic brown-earth soils in semi-shade. In particular, it is found in gaps and along tracks in deciduous woodland and among shrubs on rock outcrops. In both of its extant native sites in Britain it grows along the banks of lanes at the woodland edge. Associated species include Allium ursinum, Arum maculatum, Brachypodium sylvaticum, Carex divulsa, Crataegus monogyna, Hedera helix, Ligustrum vulgare, Melica uniflora and Rubus fruticosus (FitzGerald 1990a; Birkinshaw 1990c).
It is a tussock-forming perennial, flowering in April and May and carrying ripe seed from October to March. Unlike other British sedges, its seeds are few and very large. Inflorescences are borne at the end of long stems up to 1.2 metres tall, which may be an adaptation to disperse seeds away from the parent. Seeds can remain dormant in the soil for long periods and are stimulated to germinate by changes brought about by the opening of the canopy when old trees die (Lousley 1976). Within newly created gaps, plants may flower and set seed. As the canopy closes over, plants slowly decline and eventually disappear, leaving dormant seed in the ground awaiting the formation of a new gap. The Godalming plants apparently resulted from the germination of seeds which had lain dormant for at least twenty years (Marren & Rich 1993).
Since plant recording began, this species has always been extremely rare in Britain, having been recorded from only twelve sites. These were located in Dorset, Kent, Surrey, Somerset and Anglesey, and presumably represent relics of a once widespread species. Now, populations survive in only two locations: near Godalming, Surrey and near Axbridge, Somerset. In 1995, near Godalming, there was one large plant which bore 72 flowering stems, and two smaller plants nearby (Rich & Fairbrother 1995). In 1997 four flowering plants occurred. Near Axbridge, there were fourteen plants in 1995, but the population has been reinforced several times with cultivated native stock, and it may be that none of these plants is of natural origin. In addition, a 'back-up' population of 55 plants, originating from 100 plants translocated from Cambridge University Botanic Garden in 1988, grows close to the Axbridge population (Birkinshaw 1990c). All Axbridge plants are protected within an SSSI.
Populations of C. depauperata have declined or become extinct through woodland destruction, the cessation of traditional woodland management leading to the development of a closed canopy or a dense understorey of shrubs or bramble, and possibly the excessive collection of herbarium specimens by 19th century botanists. The habitats of the two extant populations are now being managed to maintain the favoured conditions of semi-shade. It is possible that former populations which became extinct may be resurrected by the reinstitution of suitable management (Birkinshaw 1991). The plant's occurrence by tracks indicates that it may be tolerant of trampling, or perhaps survive because other less tolerant species are suppressed.
Outside Britain, the natural distribution of C. depauperata includes southern Europe, the Crimea, the Caucasus, south-west Germany, Belgium, and southern Ireland. It seems to be rare throughout its range, and in Germany may be extinct (Blab, et al. 1984). In Belgium and Ireland only single populations are known (Delvosalle, et al. 1969; O'Mahony 1976).
C. R. Birkinshaw
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
1988. The Irish Red Data Book. 1. Vascular Plants.
1982. Sedges of the British Isles. Botanical Society of the British Isles Handbook no. 1, edn 2.
1999. British Red Data Books. 1. Vascular plants, edn 3.