maryland weather service 289 



Swamps. 



The Swamp type of forest has been examined at Wolf Gap, near 

 Finzel, at Thayerville and Cranesville, at each of which localities 

 there are small groves of virgin or old second growth trees. The 

 Swamp forest is distinctly coniferous, with the Black Spruce the 

 predominant tree and the White Pine, the Hemlock and Tamarack 

 the principal secondary species. The Black Spruce forms 60% to 

 75% of the stand; the Pine and Hemlock together, 15% to 20%; 

 the Tamarack is found at Cranesville and is abundant at Thayer- 

 ville, but is not known elsewhere in the Zone. The White Spruce 

 (Picea rubra) is reported for Garrett County by Curran, but has 

 not been seen there by the writer. The deciduous trees in the 

 Swamps are the Yellow Birch, the Red Maple, the Mountain Ash 

 and the Black Ash. 



Among very dense stands of spruce there is little shrubby vege- 

 tation, the saturated ground is covered with beds of Sphagnum , 

 Polytrichum, Thuidium and Bazzania, and there are scattered plants 

 of Osmunda cinnamomea, Spathyema foettda, Dalibarda repens, 

 Ca-rex folliculata, Osmunda regalis, Unifolium canadense, Viola 

 sagittata, Trillium erectum and Habenaria clavellata. Where 

 streams traverse the swamps or where the stand of trees is more open 

 there are dense thickets of Rhododendron maximum. Other abundant 

 shrubs are Alnus rugosa, Viburnum cassinoides, Aronia nigra, Ilex 

 verticillata, Ilicioides mucronata and Benzoin benzoin. Taxus 

 minor also occurs on moist but not on saturated soil. In the Swamps 

 at Cranesville and Thayerville the following herbaceous plants, in 

 addition to those named above, are common : 



I nipaliens biflora 

 ( 7/ clone glabra 

 Chrysosplenium am&ricanum 

 Veralrum riridc 

 Thalictrum dioicum 

 Galium triflorum 

 Panicularia nervata 

 Eupatonum purpureum 



