LOCUST, COFFEE-BEAN AND RED-BUD 197 



to Robinia but since this genus has not been recognized with cer- 

 tainty in the succeeding Eocene deposits either in this country or 

 elsewhere, these too must be considered questionable. Two species 

 of locust have been recognized in the Oligocene of Europe — one in 

 France and the other in Italy. It is in the Miocene, however, 

 that the locust becomes widespread and exceedingly common. 

 At least a dozen different species have been recognized from Euro- 

 pean deposits of this age and one of these from the late Miocene of 

 central France is so similar to the existing locust of North America 

 that its describer is disposed to consider the two as identical. This 

 form continued to exist in the European area in Pliocene times. 

 A well marked locust has also been found in the deposits of the lake- 

 basin at Florissant, Colorado, but no other North American Mio- 

 cene form has been discovered. 



In addition to the very modern looking Pliocene form already 

 mentioned a second was common at this time along the Mediter- 

 ranean coast of southern Europe from Spain to Slavonia. There is 

 no evidence that the locust survived the first glaciation in Europe 

 but in North America we find the modern species in the Interglacial 

 deposits of the Don Valley in Ontario some distance north of its 

 existing range, and it is also found in the late Pleistocene of Mary- 

 land. 



THE HONEY LOCUST (gLEDITSIA) 



The black locust is sometimes called the honey locust in New 

 England because of its fragrant nectar-bearing blossoms. The 

 true honey locust is, however, quite another tree and belongs to 

 the family Caesalpiniaceae, Robinia belonging to the family Papi- 

 HonacejE. 



The honey locust belongs to the genus Gleditsia, sometimes 

 spelled Gleditschia since it was named by Linnaeus in 1753 in 

 honor of J. T. Gleditsch, a German botanist. Gleditsia contains 

 5 or 6 species natives of eastern North America and Asia, and 3 of 

 these are found in the United States. One, Gleditsia texana, 

 Sargent, is confined to the Brazos River Valley in Texas; a second, 

 the water locust Gleditsia aguatica Marsh, is found in our southern 



