FLOWERS OF THE BOGS AND MARSHES 



185 



aerial parts above water are also exposed to 

 drought, and the bog- plants have xerophil- 

 ous adaptations, absorption of water being 

 difficult. 



Marsh plants are similarly protected and 

 enabled to withstand drought, though less 

 liable to alternations of wet and dry con- 

 ditions than bog plants. Moorland plants 

 show the most marked contrivances for re- 

 sisting drought, and the vegetation is almost 

 entirely xerophytic. 



Vestiges. Many causes have contributed to 

 the disappearance of the wet-soil types of vege- 

 tation such as bogs and marshes. The moor- 

 lands, which are drier, and situated mainly 

 above the zone of cultivation, have, however, 

 largely escaped, and they are probably of far 

 greater extent than the bog or fen type and 

 marshes. 



The fen type, since it is largely lowland, 

 and developed upon soil which is valuable 

 for agricultural purposes, has been most 

 largely affected. But in spite of this there is 

 a good deal of country in the original state 

 of the Fens. 



Bogs, lowland or upland, however, have 

 been greatly reduced in extent. The lowland 

 types now only survive in an altered condition, 

 having by artificial agency been transformed 

 into marsh or wet meadow. In some cases 

 they are to be discovered only by a careful 

 survey of the country yard by yard, or field 

 by field. The same applies also in a great 

 measure to heaths and similar vegetation 

 developed upon peat or ground with stag- 

 nant water, liable to be removed. When wet 

 peat is drained it may become a moor, or a 

 wet or dry meadow or grass heath. 



We have ventured to call such traces of 

 former bog or heath "vestiges", since they are 

 now merely an indication of natural vegeta- 

 tion almost obliterated. Marshes are similarly 

 liable to become lost or completely altered by 

 kindred causes. 



Drainage and its Effects. For agricultural 

 purposes a soil must be drained of superfluous 

 moisture. Hence practically all land below the 

 altitude of 1000 ft. has been subjected to re- 

 peated drainage, after tree-felling, followed by 

 cultivation and the enclosure of land. 



All the causes at work too, in diminishing 

 rare plants, accentuate this effect of drainage. 

 The Fens are an illustration of the extent to 

 which drainage has gone on within the last 

 two centuries. All the tract from Peterborough 

 and parts of Lincoln to Bedford and Hunting- 

 don, and most of East Anglia, has undergone 

 the most radical alteration. Where the Bittern 

 boomed and the Ruff once bred, will be found 

 acres and acres of potato fields. The reed 



swamps are gone, and so too is the marsh and 

 bog vegetation. 



The Lowland Character of Marshes. -The 

 marsh plants as a whole are of Arctic origin, 

 a large proportion of them being of northern 

 type. They are ascending species, which, 

 owing to the milder conditions since the 

 Glacial epoch, have gradually tended to reach 

 a higher altitude more suited to their primitive 

 or original requirements. 



The marsh flora in its unaltered phase de- 

 mands a lowland habitat, where water of a 

 stagnant character may rise to a certain 

 level, so that the plants may be more or less 

 submerged. The water is, however, not as 

 in aquatic vegetation able to circulate freely. 

 The marsh vegetation is thus largely above 

 the river level, and may rest upon a certain 

 amount of peat. 



Tree Associations of Marshes. That the 

 marsh vegetation is a more or less natural for- 

 mation is shown by the usual occurrence of a 

 certain tree association, which gives it a dis- 

 tinctive character. The tree flora of the moors 

 is deficient in this country, and only the Pine 

 and Birch are found at high altitudes in peaty 

 soils. In a marsh formation the Alder is 

 usually the dominant tree. The fen or fen 

 carr is also made up of Weeping Willow and 

 Sweet Gale forming a scrub, which merges 

 into an Alder and Willow wood; Ash, the 

 pedunculate Oak, the hoar}- and black Pop- 

 lars, and the small-leaved Elm also occur 

 frequently. 



The shrubs forming the scrub layer are 

 made up of the smaller W T illows, Guelder 

 Rose, Birch, Field Maple, Hawthorn, Sloe, 

 Elder, Gooseberry, Currant, and Brambles 

 and Roses, with such climbers as Honeysuckle 

 and Ivy. 



But trees may be absent, in which case 

 marsh approaches the bog formation more 

 closely. 



Marshes and Wet Meadows. The margin 

 of a marsh usually shows the wet-meadow 

 type of vegetation that results when marshes 

 are drained. The characteristic tree associa- 

 tion may remain to some extent, and Al- 

 ders and Willows are often found bordering 

 streams and rivers, or growing in hedges with 

 deep or wide ditches, flanked by meadows, 

 which have lost their most characteristic herb- 

 aceous marsh flora. 



There may be in such wet meadows relics 

 of the former marsh flora, denoted by the 

 general distribution of Marsh Marigold, Lady's 

 Smock (Cardamine amara), Ragged Robin, 

 Great Water Stitchwort, Meadow Sweet, Gol- 

 den Saxifrage, Marsh Willow Herb, Marsh 

 Bedstraw, Valerian, Marsh Thistle, Money- 



