Flora of Ashdown Forest - Botanical Society of the British Isles

190*Sagittaria latifolia. Duck-potato.Probably introduced with other aquatics, Ellison's Pond (462.288), from where it hasbeen known since 1985, AH.It has been introduced to several European countries, and is naturalized in a fewsites in southern Britain but does not seem to spread far from the initial sites. It is3 widespread as a native in wetlands in the Americas, and American Indians once used thestarchy tubers for food.4 5Alisma plantago-aquatica. Water-plantain.Common on the Forest (Hall 1980).A few scattered records in ponds around the Forest but not found in the moreacidic, nutrient-poor water.It is a widespread and very characteristic species of damp mud and shallow water3 --++---------'+- throughout the British Isles in lakes and ponds, rivers, streams and ditches. It tends togrow in open vegetation and is an early colonist of new sites. It grows especially well innutrient-rich water. In water over 65 cm deep it apparently survives vegetatively but willnot flower. The flowers are reputed to open in the afternoon.4 5It is widespread in Sussex and is native in temperate Europe and Asia.[Alisma lanceolatum. Narrow-leaved water-plantain.Once recorded in the Botanist's Pocket Book for Ashdown Forest (Wolley-Dod 1937) but not seen in our survey.Given the frequency with which it is confused with juvenile A. plantago-aquatica and its rarity in acidic water, theoriginal record must be in some doubt.It grows in similar places to A. plantago-aquatica but is generally much less common and certainly so in Sussex.It is widespread but uncommon in southern Britain, and widespread in Europe except the north. Also in western Asiaand North Africa.]Damasonium alisma. Starfruit.Ashdown Forest, New Botanist's Guide (Arnold 1887) but now long extinct.This is a Red Data Book species which used to occur on the drying mud around ponds where they were keptopen and trampled by cattle. It is no longer to be found anywhere in Sussex, and is extremely rare in England.Birkinshaw (1994) has reviewed its conservation in western Europe, and steps are being taken to conserve it in itsfew remaining sites in Surrey and Buckinghamshire; no plants were seen in Britain in 1995 (Rich et al. 1995).It occurs in western, southern and south-east Europe, Asia and North Africa, with England being its northernlimit.HYDROCHARITACEAE*Stratiotes aloides. Water soldier.Ponds in Pippingford Park at 448.299, 1995, TR and 444.301, 1993, SBRS, a deliberateintroduction in both cases.This aquatic species is noted for the unusual way in which it spends the autumnand winter submerged, and then rises to the surface in the spring and summer, but the3 --++----:~-----'-+- mechanism for this has never been satisfactorily explained (Sculthorpe 1967). Therosettes put out shoots which form little rosettes at their tips, and it can rapidly grow tofill a pond. !t is dioecious but rarely seems to flower in Britain and fruit set has not beenobserved (Mountford 1994). Fema!e plants are reputed to dominate in Britain and the4 5northern part of its range, and male plants mainly dominate in the south, but the sexesoverlap in the middle part of its range.As a native in Britain it is now largely confined to the Norfolk Broads and is a Nationally Scarce Species(Mountford 1994). In Sussex it could be native on Pevensey and Lewes levels. It has been introduced to manyplaces in the Midlands and the south-east. Widespread in Europe though rarer in the west and south, and in northwesternAsia.