BALSAM FIE. 



uted to two causes, excess of moisture and a short growing season. 

 The dense evergreen foliage of the coniferous trees, as well as the 

 ground cover of moss, shields the ice which forms in the ground 

 during winter against the rays of the sun in the spring. Thawing, 

 and therefore the root activity of the trees, begins later in the swamps, 

 often five weeks, than on the slopes or dry flats. 



The characteristic ground cover of balsam swamps is made up of 

 mosses, which form about 70 per cent of the herbaceous vegetation. 

 The character of the vegetation and the relative proportion of the 

 different species which compose the ground cover of the swamps is as 

 follows : 



Mosses (70 per cent): 

 Common — 



Sphagnum. 



Fern moss {Hylocomuim proUferum). 



Shaggy moss (Hylocomuim hiquitnim). 



Scale moss. 

 Occasional — 



CraxLe mosS'(Dicranum fuloum). 

 Fern and fern allies (10 per cent): 

 Common — 



Spmulose shield fern (Dryopteris spinulosa). 



Cinnamon fern (Osmunda cinnamomea). 



Lady fern (Asplenium felixfemina). 



Long beech fern (Phegopteris phegopteris) . 



Oak fern (Phegopteris dryopteris). 



Marsh shield fern (Dryopteris phegopteris). 



Crested shield fern (Dryopteris cristata). 



Sensitive fern (Onoclea sensibilis). 

 Rare — 



Fernata grape fern (Botrychium obliquum). 



Horsetail (Equisetum sylvaticum). 

 Flowering plants (20 per cent): 

 Common — 



Wood sorrel (Oxalis acetosella). 



Gold thread ( Coptis trifolia). 



Bnnchberry ( Cornu^ canadensis). 



Dalibarda (Dalibarda repens). 



Flowering plants (20 per cen^)— Continued. 

 Common — Continued . 



Sweet white violet( Viola tHanda palustriformis). 



Creeping snowberry ( CMogenes Inspidula). 



Clintonia ( CUntonia boreatis). 



Wild sarsaparilla (Aratta nuikaulis). 



Twin flower (Linnaea ooreaUs). 

 Occasional — 



Chickweed wintergreen ( Trientalis americana). 



Painted trillium C Trillium undulatum). 



Two-leaved Solomon's seal ( Unifolium cana- 

 dense). 

 "Rare — 



Creeping wintergreen (Qavith^ia procumbens). 



Indian pipe ( Monofropa uniflera). 

 Underbrush: 

 Common — 



Green alder (Alnus alnobettda). 



Mountain ash (Pyrus americana). 



Withe rod ( Viburnum cassinoides). 

 Occasional — 



Mountain holly (Ilicioides mucronata). 



Fetid currant (Ribes proslratum). 



Swamp honeysuckle (Lonicera oblongifolia). 



Pale laurel (Kalmia glauca). 



Mountain maple (Acer sptcatum). 



Hobble bush ( Viburnum dlnifolium). 



PLAT. 



The flat type is intermediate between the swamp and the hard- 

 wood slope. It includes the low swells adjoining wet swamps, dr 

 the gentle lower ridges, and also the knolls in wet swamps. It is 

 fairly well drained, and fern moss replaces sphagnum as the principal 

 ground cover. In essentials it is still the swamp, except that it is 

 drier. Lumbermen, in fact, call it "dry swamp." Here balsam 

 grows rapidly, becomes tall, straight, and clear-boled, attains a fair 

 diameter, and, as in the swamp, often grows pure. But the trees 

 in the dry swamp are much more subject to ground rot than in the 

 wet swamp. When it occurs in mixture its associates are red spruce, 

 yellow birch, and red maple — the two latter small and unimportant. 

 It is on the flats that the heaviest stands of balsam fir are found, 

 and here also it grows more commonly in mixture with red spruce, 

 with which it is cut and marketed for the same uses. Of the four 

 types, therefore, the flat is commercially the most important. 



