1909-10.] Flora of Scottish Lakes. 171 



Flammula and the httle R. reptans, which, however, is rather scarce 

 here ; Hydrocotyle vulgaris. Spiraea Uhnaria, Galium palustre, Deschainpsia 

 csespitosa, Hypnum fluitans, H. cuspidatum, and Aulcomnium palustre. 



Loch Leven is situated in the lowest part of a somewhat oval strath 

 called the Plain of Kinross, which is bounded by the Cleish Hills, Benarty 

 Hill, the Lomond Hills, and the Ochil Hills (fig. 114). It is somewhat 

 pear-shaped in outline, with the apex lying to the south-east. It is Sg miles 

 long b}^ 2f miles wide at the broadest part. The surface of the loch is 350 

 feet above sea level ; and as the land for some distance around is below the 

 400-feet level, it must at a former period have been very much larger. It 

 was artificially reduced in size in 1845, when its level was lowered 4i feet. 

 On account of the shallow marginal zone, this slight lowering of the level 

 reduced the area by about 1400 acres. For its size it is an extremely 

 shallow loch, the greater portion of it being less than 15 feet deep. Indeed, 

 along the east shore an area almost 3 miles long by nearly a mile broad is 

 mostly less than 9 feet deep. It has, however, two depressions, each having 

 a depth of about 80 feet, one to the west of St Serf's Island, and the other 

 to the north-east of Scart Island. If the affluent were lowered 22 feet, so 

 as to reduce the level of the loch by that amount, about 3000 acres of 

 land Avould be reclaimed. There are six islands in the loch. The largest 

 of them, called St Serf's Island, has an area of about 80 acres; it is 

 quite treeless, and is utilised as a rabbit warren. Castle Island is covered 

 with deciduous trees, and has an extent of about 5 acres (fig. 115). The 

 outline of both these islands curiousl}^ resembles that of the loch, but 

 their apices lie in the reverse direction. The other islands are quite small. 

 The shores are everywhere flat and usually sandy, particularly on the east 

 side, where the sand is sometimes blown into small dunes. More rarely the 

 shore is composed of stones, or there is no shore because meadow-land 

 comes down to the water's edge. In a few places there is a narrow zone 

 of marsh extending a considerable distance along the shore, as, for example, 

 upon both the east and south sides, opposite St Serf's Island (figs. 116 and 

 117). In many places there are large quantities of vegetable remains, chiefly 

 those of Chara and Anacharis, lying upon the shore at the winter water 

 level. The flat shores of this loch are in many parts very much exposed to 

 wind, and due to this influence is the fact that some plants which ordinarily 

 grow erect here assume a prostrate habit, such, for example, as Equisetum 

 arvense, E. palustre, Juncus bufonius, J. acutiflorus, J. supinus, Ranunculus 

 Flammula, etc. There are two or three associations of Phragmites com- 

 munis, as well as of Heleocharis palustris and Equisetum limosum, that enter 

 the water here and there, otherwise there are no plants of semi-aquatic type 



