THE MAPLE 221 



apparently always have been characteristic. The leaves are 

 superficially like those of some of the grapes or of the genus Cissus 

 and its allies, but are usually readily recognizable, and if the winged 

 fruits of the maple are at all well preserved in the rocks it is usually 

 not difiicult to distinguish them from the winged seeds of the 

 conifers, or from the somewhat similar winged fruits of certain 

 tropical genera belonging to the soapberry and banisteria families. 



A very large number of fossil maples have been described, many 

 more than are present in the Hving flora. The oldest of these 

 come from the Upper Cretaceous of western Greenland and western 

 Canada. Additional Upper Cretaceous species have been recorded 

 in Saxony and along our middle Atlantic coast but these are not 

 certainly identified. 



At the beginning of the Tertiary, however, in Eocene times, 

 maples were present in force. Over a score of different kinds have 

 been described frcm the fossil remains of beautifully preserved 

 fruits as well as the leaves. The maples had certainly reached 

 western Europe early in the Eocene, for a characteristc maple 

 key has been found in the celebrated travertine deposits of Sezanne 

 east of Paris. In America early Eocene maples have been found 

 in Yellowstone Park, Wyoming, Colorado, New Mexico and 

 Dakota. In the later Eocene, coincident with the northward 

 spread of the temperate forests of the globe, maples were abundant 

 and had penetrated northward to Alaska, where 3 forms have 

 been discovered; to Greenland where 5 different species have been 

 recorded; to Spitzbergen and Iceland. In beds of the same age 

 3 different maples have been found on the island of Sachalin north 

 of Japan; and in British Columbia, Oregon and Wyoming. 



In the succeeding Oligocene times the known maples became 

 reduced to 1 1 different forms, all of which, like so many other tree 

 types during that time, are confined to European locahties. Six 

 of these are from various Ohgocene horizons in France, 2 are from 

 Germany, and Italy, Bohemia, and Russia have each furnished a 

 single form. 



The greatest display of fossil maples throughout the Northern 

 Hemisphere occurs in deposits which were formed during the Mio- 



