1914.] NATURAL SCIENCES OF PHILADELPHIA. 465 



caroliniatia) , wild ipecac {Euphorbia ipecacuanhce) , Hudsonia ericoides, 

 sand myrtle {Dendrium huxijolium), arbutus (Epigoea repens) and 

 pyxie {Pyxidanthera barbulata), takes possession and following or 

 accompanying these are bunch-grasses, like the Andropogons and 

 rosette grasses mostly of the genus Panicum {P. conmionsianum, 

 addisoni, columbianum, etc.). These prepare the way for a low shrub 

 vegetation of blueberries and associated plants. 



The bogs of the Pine Barrens are the results, as already mentioned^ 

 of the imperfect drainage of the region. The rain-water from the 

 sands passes by seepage into the depressions and there accumulates 

 until it finds an outlet into one of the general drainage systems. 

 Owing to the low relief of the country, the Avater never accumulates 

 to any great depth and is consequently choked by a luxuriant vegeta- 

 tion of a typical peat-bog aspect. Originally, especially in the wetter 

 parts of the bogs, the dominant tree was the white cedar, Chamcecy- 

 paris thyoides, whence the term cedar-bog so frequently applied to 

 the Pine Barren bogs. In many swamps, however, this tree has been 

 largely removed and its place taken by a mixed growth, of which the 

 dominant tree is the red maple, Acer rubrum. Along with this are 

 large numbers of sour-gum, Nyssa sylvatica, and swamp magnolia, 

 M. virginiana. Beneath these is usually a dense undergrowth of 

 tall shrubs like clammy azalea, Azalea viscosa, sweet pepper bush, 

 Clethra ahiijolia, high bush-huckleberry, Vaccinium corymbosum, 

 and withe-rod, Viburnum nudum. Where the taller vegetation is 

 not too dense there is a lower undergro^siih of cinnamon fern {Osmunda 

 annamomea), royal fern {Osmunda regalis), chain fern (Woodwardia 

 virginica) chokeberry {Aronia arbutifolia), inkberry (Ilex glabra) 

 and such ericaceous shrubs as leucothoe (L. racemosa), privet 

 andromeda (Xolisma ligustrina) and cassandra {Chamadaphne 

 calyculata). In still more open places, where the shrubby growth 

 has been cut away, a varied herbaceous growth prevails consisting 

 predominantly of chain fern {Woodwardia virginica) and certain tall 

 .species of sedges and rushes {Eleocharis spp., Rhynchospora alba, 

 Eriophorum virginicum, Juncus canadensis, J. dichotomus, J. acumi- 

 natus, J. effusus, etc.). Cushions of bog-moss {Sphagmim spp.) 

 are frequent about the bases of these plants and in these grow several 

 species of sundew {Drosera). Other plants not infrequent in these 

 places are swamp pink {Helonias bullata), Avhite fringed orchid 

 {Blephoriglottis blephariglottis), rose pogonia {Pogonia ophioglossoides), 

 grass-pink {Limodorum tuberosum) and the cranberry {Oxycoccus 

 macrocarpon) . 



