Flora of Ashdown Forest - Botanical Society of the British Isles

29EQUISETACEAEEquisetum f/uviatile. Water horsetail.Six tetrads (Hall 1980).Recorded frequently from the wetter valleys south of Forest Row, at Old Lodge and in apond in the corner of Furnace Wood. Almost all localities are in ponds, often where there isother vegetation and bottoms choked with silt, or in gentle flushes in some of the springs.3 Many of the sites are shaded. It has been suggested to be particularly abundant in marl pitsbut this has not been confirmed.It is widespread in Britain from the rich ditch systems of Sussex grazing marshes such asPevensey Levels, to clear nutrient-poor lakes in Scotland. Jermy et al. (1978) note the ecology4 5is little understood. It is widespread in Europe, temperate Asia and North America.Equisetum x litorale (E. fluviatile x palustre). Shore horsetail.Ashdown Forest, c. 1955, R. A. Boniface (BRC). Not refound.Jermy et al. (1978) note that this hybrid is surprisingly frequent in Britain and Ireland given the dissimilarity of thehabitats of the parents. There is a distinct cluster of records in the north Weald which is probably due to the efforts of asingle recorder.Equisetum arvense. Field horsetail.Common in tetrads around the edges of the Forest (Hall 1980).We have recorded 'It quite widely in arable fields, gardens, waste ground around the edgesof the Flora area, and on roadsides on the Forest. It is distinctly uncommon on the Forest.Common and widespread in Britain, and recorded in Europe, central China, North America3 and Greenland.4 5Equisetum palustre. Marsh horsetail.Tetrads 33V, 43F and 431< (Hall 1980).Recorded from scattered squares around the edge of the Forest, and in the Chelwoodarea. Jermy et al. (1978) note that it requires moving ground water with a medium basecontent(calcium/magnesium), and it may occur where the soils are less acidic.3 -+-l---....-------Y- It is frequent in Sussex, and common and widespread in Britain, Europe, temperate Asiaand North America.4 5Equisetum telmateia. Great horsetail.Recorded from tetrads 42N, 43K, 43L, 43M and 43V in Hall (1980), some of which may have been from outside our area,but oddly not recorded at all during our survey. This species often occurs on wet clays in Sussex often by spring lineswhere there is some water seepage, a habitat not present in most of Hall's tetrads on the Forest. It is found locallythroughout Europe, Asia, North Africa and North America.OPHIOGLOSSACEAEOphioglossum vulgatum. Adder's-tongue.Tetrads 43G (Hall 1980) and 42T (Briggs 1990), and refound in both.The main habitat on Ashdown Forest is on the more floristically-rich verges, clearly wherethere is some base-enrichment from the road, and some patches may be 5 metres long.Twyford Lane (404.314), 1995, CM; near Goat cross roads (402.325), 1993, TR & NM; Priory3 Road (405.328), c. 1993, CM; both sides of Hindleap Road (418.319), 1995, CM; A275 nearWych Cross Place (419.315), 1990, CM; thousands on private meadows and lawns, OldCherry Cottage (41.33 and 42.33), 1995, PS; Chelwood Vachery drive (435.304), 1993, TR &4 5 NM; east of the Visitor Centre (434.323), 1992, NM and 1995, CM; verge 30 metres NE ofcar park, Gills Lap (468.315),1995, TR; verge 100 metres west of Greenwood Gate(478.314), 1995, TR; Poundgate verge (482.285), 1995, CM, big colony, 1995, PS; two fronds, Toll Lane wood(461.263), 1993, TR & NM, not refound SUbsequently.This small, grass-green fern is very difficult to see, and is probably generally under-recorded (e.g. Briggs 1990 gaveabout twice as many records for Sussex as HaJl 1980). It is found most easily in April or May before the vegetation closesover, and the fronds have usually died down by the end of June or been mown.