836 



SCIENCE. 



[N. S. Vol. XII. No. 309. 



2. Plants, probably not of neotropical 

 origin, which are, in several cases, probably 

 the more or less modified descendants of 

 that characteristic flora which in later 

 Eocene or in Miocene time extended to 

 high northern latitudes, also occupying the 

 mountainous parts of what is now the North 

 Temperate Zone.* Of this category, the 

 number of identical species occurring both 

 in the Coastal Plain and in the Appalach- 

 ian region is notably smaller than in the 

 first group. To be reckoned here, with 

 more or less confidence, are : 



Danthonia sericea. 



Uniola gracilis. 



Uniola longifoUa. 



Poa CJiapmaniana. 



Arundinaria Tnacrosperma (?). 



Arundinaria teeta (?) 



Lilium earolinanum. 



Ulmtts alata. 



Pamassia grandifolia. 



Decumaria barbara. 



Itea mrginica. 



OratcBgus uniflora. 



Cratmgus rotundifolia. 



Berchemia scandens. 



Ampelopsis cordata. 



Vitis rotundifolia. 



Aralia spiiiosa. 



Dendrium bii.mfolium [Leiophyllum). 



Leucotiioe racemoaa. 



Oxydendrum arboreum. 



Oaylussaeia dumosa. 



Vaccinium arboreum. 



Symplocos tinctoria. 



Ohionanthus virginica. 



Antennaria soliiaria. 



Most of the species, as well as many of 



* According to De Saporta et Marion (Recherohes 

 BUT les v^g6tanx fossilea de Meximienx ; Arcliiv. 

 Mns. Hist Nat. de Lyon, 1 : 304-324 (1875), a vege- 

 tation of Magnolia, Laiiracese, Liquidambar, Anona- 

 ceje, Ilicaceie, Liriodendron, etc., occurred on the 

 mountains of southeastern France, at altitudes of 200 

 to 700 meters, during the Pliocene. That a similar 

 flora flourished contemporaneously in the mountains 

 of eastern North America would seem by no means 

 unlikely. If so, the Pliocene flora of the Appalachian 

 legion must have borne considerable resemblance to 

 that which prevails there to-day. 



the genera, comprised in this second cate- 

 gory are characteristic neither of tropical nor 

 of high northern regions. They belong in 

 great part to groups which are most largely 

 represented at present in the mountainous 

 parts of the Warm Belt of the Northern 

 Temperate Zone, in both the Eastern and 

 Western Hemispheres. Some of them, how- 

 ever, are of floral types which are to-day 

 most highly developed in the tropics. Such 

 are the species of Arundinaria, Berchemia 

 scandens, Ampelopsis cordata, Aralia spinosa 

 and Symplocos tinctoria. Yet the groups to 

 which several or all of these species belong, 

 formerly had a much wider extra- tropical 

 distribution than is now the case. A few 

 plants of this category, i. e., the species of 

 Poa, Pamassia and Antennaria belong to 

 genera of mainly boreal and alpine distri- 

 bution. 



To be considered in connection with this 

 second category of the Lower Austral spe- 

 cies which occur both within the main lim- 

 its of the Austro-riparian area and in the 

 mountains, is a very significant group of 

 genera which are represented in eastern 

 North America by two closely allied species 

 or group of species, one in the Coastal Plain, 

 the other in the Appalachian region. 



With the exception of Clethra (which is 

 largely tropical) all these genera, like many 

 of those represented by species of the 

 second category, have their present center of 

 distribution in the warmer part of the North 

 Temperate Zone. This may be said also of 

 the larger groups to which many of them 

 belong, e. g., the families Calycanthacese, 

 Sarraeeniacese, Hamamelidacese and Mono- 

 tropacese, and the tribes Hydrangese of 

 Saxifragacese and Andromedese of Ericaceae. 

 Some of them are known to belong to floral 

 types which were very widely distributed in 

 the Northern Hemisphere during the earlier 

 part of the Tertiary, in not a few cases 

 ranging as far north as Greenland and 

 Alaska ; and we may be permitted to con- 



