NO. 2256. FOSSIL PLANTS FROM OKLAHOMA— BERRY. 631 



Order ROSALES. 



Family CAESALPINIACEAE. 



Genus GYMNOCLADUS Lamarck. 



GYMNOCLADUS CASEI, new species. 



Plate 94, fig. 2. 



Leaflets sessile, relatively small in size, somewhat inequilateral 

 ovate in general outline, with a short acuminate tip and a rounded 

 base. Margins entire. Texture subcoriaceous. Length 3.5 cm. 

 Maximum width, below the middle of the leaflet, 1.7 cm. Midrib 

 stout, prominent, slightly curved. Secondaries comprising about 

 four subopposite to alternate pairs, camptodrome ; they diverge from 

 the midrib at angles of about 45 degrees and curve regularly upward 

 subparallel with the lower lateral margins. The character of the 

 matrix has obliterated the areolation. 



The present material is clearly to be affiliated with the leaflets of 

 the existing Gymnocladus dioicus Koch, the Kentucky Coffee tree, 

 differing from the latter principally in the slightly smaller size of 

 the fossil leaflets. Gymnocladus has but two existing species, the 

 one just mentioned and a second in southern China. This distribu- 

 tion in itself and from the analogy furnished by other genera such as 

 Magnolia, Liriodendron, Sassafras, and Liquidarribar, likewise found 

 in eastern North America and eastern Asia, and with more or less 

 of their geological history known, is conclusive evidence that Gymno- 

 cladus had a Tertiary history during which it occupied intervening 

 areas. However, with the exception of the species just described and 

 some rather doubtful European records ^ no fossil remains have thus 

 far been discovered. 



Gyrmiocladus dioicus {G. canadensis Lamarck), the existing 

 American species, is a member of the mixed deciduous forests of 

 southeastern North America, ranging from central New York and 

 western Pennsylvania and Maryland through southern Ontario and 

 southern Michigan to the valley of the Minnesota River and to the 

 bottoms of the larger rivers in eastern Nebraska, eastern Kansas, 

 and eastern Oklahoma. It is distinctly an alluvial species through- 

 out its range and while plant geographers record it and other species 

 of like habitat as invaders into the prairie region from the east it 

 is certain that they or their immediate ancestors had a much more 

 extensive range in the late Tertiary in what is now the prairie 

 country. 

 Eolotype.—C2.t. No. 35285. U.S.N.M. 



iHeer, O., Fl. Tert. Helv., vol. 3, 1859, p. 103, pi. 134, flgs. 9-12. Squinabol, S., La 

 Flore de Novale, 1901, p. 71, pi. 4, fig. 15. 



