Berry — Engelhardtia from the American Eocene. 491 



Aet. XL. — An Engelhardtia from the American Eocene; 

 by Edward W. Beery. 



The walnut family (Juglandacea?), which in the popular 

 mind is fully rounded out by the enumeration of the walnut, 

 butternut, hickory and pignut, consists of six or seven genera 

 and about forty species scattered throughout the warmer parts 

 of the north temperate zone and penetrating some distance 

 south of the equator along the Andes in South America and 

 in the East Indies. The Juglandacese are of considerable 

 interest for a variety of reasons, chief among which, aside from 

 their great economic importance, are their line of ancestors 

 reaching back to the mid-Cretaceous, and because of the much 

 discussed question as to whether their morphological characters 

 shall be interpreted as primitive or as mere simplifications of 

 a more highly organized stock. 



All of the genera have not adopted the same methods of 

 dissemination and certain tropical and sub-tropical genera 

 have kept the seed part of their fruits comparatively small and 

 light, thus enabling them to produce large numbers of seeds 

 with the same expenditure of energy required for a single wal- 

 nut. Furthermore, instead of depending upon chance for the 

 distribution of their latent progeny, the bracts which are nor- 

 mally present throughout the family have developed enor- 

 mously and serve as wings. This is especially true of the genus 

 Engelhardtia, a recent addition to Avhich is the occasion for the 

 present brief note. 



The genus Engelhardtia was described by Leschen in 1825 

 and contains about ten species of the southeastern Asiatic region. 

 These range from the northwestern Himalayas through farther 

 India and Burma to Java and the Philippines. The pistillate 

 flowers are small and are grouped in paniculate spikes. They 

 develop into small drupe-like fruits, each of which is connate 

 at the base to a large expanded tri-alate involucre. 



A single little known species rarely represented in even the 

 larger herbaria occurs in Central America and is the type and 

 only species of the genus Oreomunnea of Oersted. This is 

 much more restricted in its range than are its kin beyond the 

 Pacific. Oreomunnea is very close to Engelhardtia, and for 

 the purposes of the paleobotanist the two may be considered 

 as identical since they represent the but slightly modified de- 

 scendants of a common ancestry which was of cosmopolitan 

 distribution during the early Tertiary. The present isolation 

 of Oreomunnea furnishes a striking illustration of the enor- 

 mous changes which have taken place in the flora of the world 



