112 COULTER AND ROSE 



genera. These eighteen genera have added sixty-four species 

 to the flora of the region under consideration, while numerous 

 species have been added to other genera, notably to Eryngium^ 

 Tausckia, and Arracacia. The Umbelliferae of Mexico and 

 Central America, therefore, are now known to include thirty- 

 nine genera and one hundred and eighty-two native species, 

 which more than doubles the species known in 1886. It is 

 also of interest to note that ten of the genera and one hundred 

 and forty-eight of the species are endemic. 



Certain features of geographical distribution have become 

 evident, but exploration must be more complete before they can 

 become very definite. There are very few Umbelliferge in the 

 tropical zone of Mexico and Central America, their chief de- 

 velopment being in the mountains of the Upper Austral and 

 Transition zones, in such dominant forms as Eryngium, Arra- 

 cacia, Prionosciadium , Tauschta, Coulterophytum^ and Rhodo- 

 sciadium, the Sierra Madre region having proved most produc- 

 tive of new forms. It is also a matter of interest that the great 

 dominant genus of the Western United States, Peucedanum, 

 with its 60 or 70 species, is probably not represented at all south 

 of the Mexican boundar3^ 



In the Co7itributions of the National Herbaritim (3 : 289- 

 309. 1895) we gave an account of new and noteworthy species, 

 largely bringing together the knowledge of the group which 

 had accumulated since Hemsley's account of 1880. Since 1895, 

 however, exploration has proceeded rapidly, and many new col- 

 lections have not only contributed numerous new species, but 

 have also thrown much light upon certain genera and doubtful 

 species. The recent collections which have contributed chiefly 

 to our knowledge are as follows : 



The veteran collector Mr. C. G. Pringle, whose annual sets 

 of Mexican plants for twenty years have been among the most 

 valuable additions to herbaria, in recent years has been working 

 chiefly in the general region of the City of Mexico, which has 

 been made accessible by the opening up of new railway lines. 



Messrs. E. W. Nelson and E. A. Goldman, field naturalists 

 of the Biological Survey of the U. S. Department of Agricul- 

 ture, have collected over a more extensive area than any others. 



