. Macbride — Certain North American Umbelliferae 29 
names presented without further question. In the present in- 
stance, however, I have found myself involved in an analysis of 
the group of segregate genera listed above because of the lack, in 
any one treatment by Coulter & Rose, of a presentation in con- 
trast of the characters relied upon by them to distinguish these 
several genera. Treatment of the Mexican genera apart from 
those of the United States has been responsible for this unfortu- 
nate situation. 
Tauschia, as defined by Coulter & Rose, Proc. Wash. Acad. Sci. 
i. 134 (1900), is made to include only Mexican species which are, 
1. c. 134, “ of low acaulescent habit, with pinnate leaves, obtuse 
ribs, and no stylopodium.” After reading this statement it is 
rather startling to say the least to note that the species are divided 
in the key into two subgroups, one containing plants that are 
“ Acaulescent or weak caulescent,” the other, those that are 
“Caulescent, rather stout and somewhat branching.” A similar 
instance in which the generic definition does not accord with the 
facts exists in the argument for the validity of Drudeophytum Coult. 
& Rose, Contrib. U.S. Nat. Herb. vii. 80 (1900), which, we are told, 
“differs from Deweya, however, in having orbicular fruit, with 
slender filiform ribs and ternate leaves.’”’ In the original diagnosis, 
too, occurs the statement, ‘‘ Fruit orbicular.” Yet D. Parishit 
Coult. & Rose, a species referred by the authors to Drudeophytum 
without question, has oblong fruit; and indeed the fruit is so 
described, 1. ¢. 82. Furthermore, so long as D. vestitum is retained 
in Drudeophytum, this genus cannot be said to differ from Deweya 
in having ternate leaves for, as Coulter & Rose remark, the leaves 
of D. vestitum are pinnate. The only constant character left then 
¢ distinguish Drudeophytum from Deweya is the character of 
“slender filiform ribs ” and this feature cannot be said to possess 
in itself generic value since species in related genera show varia- 
tion in the thinness and prominence of the ribs. Besides the dif- 
ference between the ribs of the mature fruit of Drudeophytum 
Parishii and those of Deweya arguta is, it seems to me, without 
question purely a relative difference. The possibility of creating 
@ new genus to care for the aberrant (and troublesome) D. vestitum 
May come in for te but such a disposition would be 
highly artificial since the plant possesses no characters that are 
admitted as being of value for the definition of genera in the Um- 
