INTRODUCTION 



A flora of 1,200 species in a limited area is considered 

 rich ; when 334 species are added to this number there is 

 cause for wonder to botanists not familiar with the topography 

 of the country from which the local flora has been collected 

 and preserved in the Herbarium in the Everhart Museum. The 

 heart of the Northern Alleghenies, where the tributaries of the 

 Susquehanna, Lehigh and Delaware Rivers have their rise, is a 

 beautiful country with a variety of soil and varying altitudes. 

 We have many lakes, creeks, tangled swamps and bogs, dry 

 barrens, rocks, valleys, plains and mountain peaks, with drift 

 heaps of the glacial age. This varied topography affords local 

 characteristic types as well as the plants common throughout the 

 Appalachian region. On Bald Mount, Elk Hills, Penobscot, 

 Pocono and Tilbury Knobs, and the Pocono Plateau and marshes 

 we have rare plants of the glacial age. We have Atlantic slope 

 species whose western limits of distribution are within our border 

 as well as Southern and Southwestern species which extend no 

 farther north or northeast. Over fifty-five northern species, 

 mainly heaths and sedges, are found here which do not extend 

 south of our territory. 



Among the more notable species included in our flora, and 

 represented in the "Alfred Twining Herbarium," are the Arce- 

 uthobium pusillum, Potentilla tridentata, Linnaea borealis, Vac- 

 cinium canadense, Opuntia vulgaris, Picea mariana, Menyanthes 

 trifoliata, Liatris scariosa. Ledum latifolium, Rhodora canadense, 

 Andromeda polifolia, Kalmia glauca. Rhododendron viscosum 

 Gaylussacia frondosa, Chiogenes hispidula, Orontium aquaticum, 

 Melanthium latifolium, Amianthium muscaetoxicum, Arenaria 

 groenlandica, Cunila mariana, Pinus inops, Sedum roseum, 

 Asplenium montanum, and Lycopodium selago. 



While the leguminous species are rare on the Pocono they 

 are abundant in the two valleys. Quite a number of plants which 

 predominate in the country immediately outside the Lackawanna 



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