Flora of Ashdown Forest - Botanical Society of the British Isles

64*Hypericum x inodorum group. Tall tutsan.One large clump by footpath west of road, Chelwood Gate (412.299),1994, TR; dumpedgarden rubbish'near Stone Cottage (447.327), 1995, TR & PA; three places down stream inKeyward's Wood (c. 502.325), 1995, TR. Hall (1980) gives two records in Sussex.The variation is due mainly to the H. hircinum parent. They are occasionally naturalized3 as garden escapes throughout the country,4 5Hypericum perforatum. Perforate 8t John's~wort.Very common on the Forest (Hall 1980).Widespread around the Forest on verges, on clays and in the· more base-rich places butquite absent from acidic heath. !t has a wide ecological amplitude, and occurs on a range ofsoil types in grassland, verges and waste ground, and in some very dry sites. Grime et al.(1988) note that its grassland distribution is biased towards burnt sites. Shoots grown in4 5strong sunlight are poisonous to stockWidespread in lowland Britain north to southern Scotland. Europe, temperate Asia andNorth Africa. A noxious weed in Australasia, South Africa, California, Iraq, etc.Hypericum x desetangsii (H. maculatum x perforatum).,---;---===-----;-, Ashdown Forest, 1983, BSBI Meeting (confirmed by N. K. B. Robson), seen again in 1984,DB, but not present in 1990.We have only one recent record; Forest Row (423.341), 1995, DB & PD, but it is alsoknown from the old railway line outside our survey area. Plants with two strong and two3 +t--------'4- weak ridges on the stems, and acute or apiculate sepals should be checked for this hybrid.Crackles (1990) notes that it is a very variable hybrid which may be widespread on railways.It is apparently rare in Sussex (Hall 1980), and is scattered through Britain. It is alsorecorded in Europe.4 5Hypericum maculatum subsp. obtusiusculum. Imperforate St John's-wort.Forest Row, Miss K. Pickard (Wolley-Ood 1937). Frequent on Ashdown Forest (Hall 1980).We have recorded it scattered around the Forest on verges, banks, etc., preferringmore acidic soils than H. perforatum. This species or its hybrid with H. perforatum is quitefrequent along the old railway line at Forest Row. Inflorescences from there are collected to3 make aromotherapy oil which is apparently good for treating aches and pains - the flowers45turn the oil a brilliant red.Frequent on the sands and clays in the north of East Sussex but rarer elsewhere. Thedistribution of this plant in Britain is oddly clustered in the Weald, central Wales and thewest Midlands, in northern England, and also in southern Ireland. It is widespread in lowlandandmontane Europe, with subsp. maculatum in Europe and as far east as western Siberia.Hypericum tetrapterum. Square-stalked St John's-wort.Frequent on the Forest (Hall 1980).Widely scattered on the Forest, normally occurring only as a few plants. It is usuallyfound in the wetter grasslands or around ponds on clayey soils, and sometimes also onwoodland rides where it reappears after disturbance but slowly decreases in frequency as3 the rides grow over again.Widespread in lowland Britain, and in Europe east to the Caucasus and in North Africa.4 5