Hill: Penobscot Vegetation 419 



Osmund a Claytoniana Microstylis unifolia 



Scirpus atroeinctus Polygonum Hydropiper 



Juneus effusus vars. Ranunculus repens 



Habenaria clavellata Drosera rotundifolia 



Spiranthes Romanzoffiana Lycopus uniflorus 



Trees such as the red spruce and larch may be present as 

 isolated individuals. 



A third type of poorly-drained swamp is found on the 

 summits of the hills and other exposed rock surfaces, where it 

 occupies little hollows and depressions in the rock. In some 

 cases the bottom of these may be muddy and there is a vig- 

 orous growth of rushes, particularly Juneus brevicaudatus. 

 More often sphagnums are present and these alter the char- 

 acter of the vegetation in the hollows. During a rain the 

 sphagnums absorb moisture and remain saturated long after 

 all water has been evaporated from the rest of the rock sur- 

 face. This enables several species to maintain a foothold, 

 which otherwise would be unable to do so. Among such 

 plants may be mentioned Eriophorum tenellum, Eleoeliaris 

 tenuis, Carew canescens var. disjuncta, Cared- trisperma and 

 the cranberry, together with several shrubs, Rhododendron 

 canadense, Myrica Gale, Xemopanthus mucrcnata and 

 Spiraea latifolia, which seem quite out of place on a rocky 

 hill top side by side with species like Kalmia angustifolia, 

 and Gaylussacia baceata (Figure 45). These miniature 

 bogs may even support a stunted growth of trees, as shown 

 in Figure 46. In this instance red spruce, larch and gray 

 birch are prominent. 



2. Formations of Lakes, Poxds, axd Swamps Along 

 the Seacoast 



The formations along the seacoast belonging to the hy- 

 drarch series comprise the barrier-beach ponds, salt marsh- 

 es, and brackish marshes. In these areas the plant life is 

 influenced to a varying degree by the sea. From the stand- 

 point of physiography they are all examples of depositing 



