Flora of Ashdown Forest - Botanical Society of the British Isles

122Epilobium obscurum. Short-fruited willowherb.Common in our survey, especially toward the west of the Forest. Generally in rather damp,places.Care is needed to distinguish this species from E. tetragonum. The glandular hairs on thecalyx tube which indicate E. obscurum are very inconspicuous and careful examination,preferably with a lens having a magnification greater than x 10, is necessary in order todifferentiate correctly between the two species.Locally common over the whole of Britain and much of Europe, also North Africa,Madeira and the Caucasus.Epilobium roseum, Pale willowherb.Chelwood Common, Miss M, Cobbe, and Forest Row (Wolley-Dod 19371, Tetrad 43F (Hall1980),One plant by road to Chelwood Farm (426,287), 1994, TR; locally frequent in Forest Rowon edges of pavements and flower beds, especially near the old school (427,349), 1993-1995, ;3 TR,It occurs throughout lowland Britain, Europe and Asia Minor.4 5*Epilobium ciliatum (Epilobium adenocaulon). American willowherb.Widespread in Hall (1980) and similarly common in our survey. This is in marked contrast tothe situation in Wolley~Dod (1937) who has only five records for the whole of Sussex.Usually found on road banks and waste places. The gaps in its distribution correspond4 5mainly to the areas of the Forest with the highest proportion of heathland. Its distribution isvery similar to a number of weedy species like Atnplex prostrata and Sonchus oleraceus. Notonly is it now a common species but forms a range of hybrids, indeed most of our Epilobiumhybrid records have E. ciliatum as one of the parents.Preston (1986) reviewed the records for this species and noted that, although it was firstcollected in Britain in 1891, it was not recognised until the 1930s. The first description waspublished in 1935, and after that it was found more widely, reaching Wales by 1942, Scotland by 1957 and Ireland by1958. The colonisation seems to have been by continuous spread in contrast to that of Senecio squalidus.A native of North America, well established in south~east England and spreading (Rich & Woodruff 1996).£pi/obium palustre. Marsh willowherb.Coleman's Hatch, H, 5, Salt (Wolley-Dod (1937). Tetrads 42T, 43K and 43V (Hall 1980),We have only two records from our survey. The first is from a flush at Newbridge(457.325) close to the site of Galium u/iginosum where several plants were found growing ina mat of Hydrocotyle vulgaris by AK and AH in August 1994. The second record is for a3 -++_----..l-+_ single plant found in a rushy flush in unimproved pasture at Brown Knoll (487.299) during oneof the Flora meetings in 1995.Epilobium palustre is a calcifuge. It occurs in wet places throughout Britain and isscattered thinly throughout much of East and West Sussex. Locally common throughout4 5Britain and widespread in Europe, Asia, North America and Greenland.It can be confused with other Epilobium species, especially E. obscurum from which it can be distinguished by thecomplete absence of raised ridges on the stem and the presence of a short appendage at the hairy end of the seed, afeature which is clearly illustrated in Stace (1991).*Epilobium brunnescens. New Zealand willowherb.Hall (1980) shows it in tetrads, 42N and 43H but it was not found during our survey, which is perhaps surprising as thisintroduction from New Zealand is still spreading in Britain. It is most common in the north and west and may beclimatically limited in the south-east.Chamerian angustifalium. Rosebay willowherb, Fireweed.Almost ubiquitous in our survey, as it was in Hall (1980) and WolleY-Dod (1937). A nativeplant once mostly of rocky gullies in northern Britain, now widespread everywhere. Thespread is attributed to the creation of suitable ground such as railway banks and road sides,and studies have shown that it is not the result of an alien genotype being naturalized as isoften thought (Myerscough 1980), Coleman (1836) only gave one site at Plaw Wood, whereit still occurs today. By the time Arnold published his flora in 1887 it was still uncommon asindividual records are given (none of which are from the Flora area). Since then it has becomeone of our most familiar wild plants with its showy flower spikes brightening a range of open