Flora of Ashdown Forest - Botanical Society of the British Isles

Myriophyllum alterniflorum. Alternate water-milfoil.Pond near Coleman's Hatch, C. E. Salmon (Wolley-Dod 19371.One isolated record in the fishing lake at Forest Row (422.3471. 1995, TR, and then aseries of ponds and streams along the Pippingford watercourse downstream from the pond inChelwood Vachery (431.2951. 1995, MR, PR & TR, to pond in Mill Wood (437.2881, 1995,MM & TR, to a pond (448.2991 and several lakes (44.301 in Pippingford Park, 1995, SBRSetc, In 1995 it flowered freely, possibly because of the warm weather.This was recorded in Hall (1980) from five tetrads just south-west of the Forest but noton it, and in Sussex is quite a rare plant. It tends to occur in base-poor and nutrient-poor4 5water such as drains from the acidic, uncultivated areas of the Forest, and is most frequent inthe north and west of Britain. Mainly in west, north and central Europe, Greenland and the Azores.GUNNERACEAE[Gunnera manicata. Brazilian giant-rhubarb.Bottom of Dodd's Hill (450.2691, 1995, AK. Planted around pond at Chelwood Vachery (431.2971, 1994, TR, but notnaturalized. The species is spreading vegetatively in damp woodlands and meadows in a number of parts of Britain, andspreading by seed in the Channel Islands and western Ireland. It is native in southern BrazilJLYTHRACEAELythrum salicaria. Purple loosestrife.Tetrads 43H and 43M along the Medway (Hall 19801.One plant in wood east of ford at Shalesbrook (435.3421. 1995, PW; damp ground onfield edge near Lines Farm (443.348), 1995, Flora meeting; several clumps in dryish ditch atbottom of Oldlands Hall formal gardens (476.2741. 1995, R. Barley et al.; Pound gate (48.281,3 1994, TR.Mainly in the main rivers and associated wetlands in Sussex (Hall 1980), and quitewidespread in the lowlands of Britain. It is decreasing in England (Rich & Woodruff 1996).Widespread in Europe except the far north, Asia and North Africa.4 5 This beautiful purplish-pink plant was introduced to North America in the 1800s, andnow billions of plants blanket many of their finest wetlands. Plants can produce 2.7 million seeds annually which aredispersed by water, animals and birds, and it is a severe threat to the natural flora and fauna as nothing there eats it. Agood biological control agent would be worth patenting!Lythrum portula. Water-purslane.Considering that it was only recorded in tetrad 43L in Hall (1980) when it must have beenoverlooked, we have recorded it very widely. It is very characteristic of the wet hollows inmuddy tracks, and in shallow ponds with base-poor and nutrient-poor water. In the hotsummer of 1995 it was conspicuous turning reddish as it dried, but still we only added aproportional one third of records so not necessarily more abundant in dry years.Scattered throughout the Weald in wet places in open communities, and possibly the areain which it is most common in Britain. Widespread in Europe except the far north, Siberia andthe Azores.This species shows a cline in the length of the calyx segments ~Allen 1954), with plantsin western Britain and Europe having them 1.5-2 mm long (subsp. longidentata) compared to 0.5 mm in plants fromelsewhere (subsp. portula), though why is unknown. Plants from Jack Daw had very short calyx segments, but they arelonger in other plants; we have not investigated them in detail.THYMELAEACEAEDaphne laureola. Spurge-Iaurel.One plant on eastern edge of Courtland Wood (451.2611, 1995, TR; five plants by Marlpits(467.2641. 1993, TR & NM.The occurrence of this 'calcicole' at the Marlpits might be expected to be related tocalcareous clay, yet the pH of the clay was 3.9 and the leaf litter around was 4.6 (these were3 -1---1-------1.--1- double-checkedl, and at Courtland Wood pH 5.3. At Marlpits the plants were also quitedamaged by grazing with many weak shoots, and they flowered only very sparsely.4 5Mainly in woodlands on the chalk in Sussex, and rarer on the clays in the Weald (Hall1980). Locally common in England and Wales in chalk and limestone woodlands. It reachesits northern-most distribution in Britain, and occurs in southern and western Europe andtemperate Asia.119