The Forth saltmarshes occur as a more or less continuous strip on the south bank of the middle Forth and as scattered fragments of varying sizes elsewhere on the banks of the estuary and the Firth of Forth. The most complex and important from a conservation viewpoint are those at Aberlady and Tyninghame. Floristically the Forth saltmarshes are poor and lack several plant species which are imporant in England, notably Halimione portulacoides and Limonium vulgare (the latter recently extinct at Aberlady). Most of the Forth saltmarsh vegetation apparently falls into the two most common and widespread Associations of British saltmarshes, Puccinellietum maritimae and Juncetum gerardii, although several other community types occur. The most distinctive features of the Forth saltmarshes are: (a) the presence of the physiographically distinct and nationally rare beach-head saltmarshes; (b) the occurrence locally of community types which have a predominantly northern or southern distribution in Britain; and (c) communities which are subtly different from more widespread examples nationally.