118 PROCEEDINGS OF THE ACADEMY OF [April,.. 



with fringed but simple lips, namely the white, large yellow, and 

 small yellow fringed orchids, H. blephariglottis, H. ciliaris; and H. 

 cristata, respectively, are extremely abundant in the bogs of that 

 area. On the other hand the species with three-parted lips, the 

 green, large purple, small purple, and short-fringed purple fringed 

 orchids, H. lacera, H. grandiflora, H. psycodes, and H. peramoena, 

 are limited to the areas surrounding the Pine-barrens, where they 

 find soils of lower acidity. 



The majority of the buttercup family, Ranunculaceae, appear in 

 other regions to be partial to circumneutral soils, and it is a striking 

 fact that members of this family are almost unknown in the Pine- 

 barren area. The marsh marigold, Caltha palustris, has been ob- 

 served in the Lindenwold bog, but it grows only at the lower levels, 

 where the soil is circumneutral. The columbine, Aquilegia canadensis, 

 can withstand a mediacid reaction if the salt content of the soils 

 is high enough, as in the Coastal area. 



The Heath family, Ericaceae, together with certain closely related 

 ones, are treated in detail elsewhere; but it may be noted here 

 how strikingly their distribution is controlled by the soil acidity. 

 The Pyrolas favor subacid soils, and are very rare in the Pine-barrens 

 though common in the Marl area. The same is true of the pink 

 azalea. Azalea riudiflora, the deerberry, Polycodium stamineum, and 

 the narrow-leaved low-bush blueberry, Vaccmium pennsylvanicum 

 (angustifolium) . Numerous other members of the family are, how- 

 ever, more abundant in the Pine-barrens than in any other area, 

 evidently because of their preference for soils low in salts and 

 high in acidity. When these ericaceous species grow in the Marl 

 area, they avoid the places where calcareous marly strata actually 

 outcrop, and grow instead upon patches of acid Pensauken sand. 



Bearing of Soil Reaction on the Origin of the Pine Barren Flora 



In papers cited in connection with table 1 , Harshberger and Taylor 

 have independently elaborated a theory of origin of the flora of the 

 New Jersey Pine-barrens, based on the alleged remaining above 

 sea-level of the Miocene strata ever since their first emergence at 

 the close of the Miocene period. According to this theory, the area 

 occupied by these strata has been an island up to comparatively 

 recent geological time, and the plants now growing there represent 

 direct descendants of those of the Miocene period. This theory 

 has been criticized from the botanical standpoint by Fernald, Har- 

 per, and others, and recent advances in geological knowledge are 



