
Macbride — Certain North American Umbelliferae 31 
question its standing as a species of Museniopsis. One other 
genus of this group is to be considered. This is Donnellsmithia 
which, now that more species of Museniopsis have been discovered, 
is evidently referable to that genus. Its only characters are, in 
nature, relative, and the fact that it is the only species known from 
Guatamala, can scarcely be interpreted as meaning that it merits 
generic recognition. 
The facts brought out above prove conclusively, it seems to me, 
the futility of treating these several evidently poorly marked 
groups of species as distinct genera. Whatever one’s theory as 
to generic limitation, no one admits that there is any advantage 
to segregation which results in the erection of genera with lines so 
indefinite that many species cannot with confidence be referred — 
toany particular group. Furthermore, if these five genera we have 
been considering are maintained we should need, if consistent in 
our segregation, several new generic names to care for aberrant 
species — species which possess the same sort of distinctive char- 
acters we are using in discriminating these five genera. And if 
these characters are of value for the discrimination of genera in 
one instance, they must, logically, be of equal value in another. 
On the other hand, to retain these merging groups in one genus 
which is at once distinct from its nearest relative, Arracacia, does 
away with the necessity of assigning in unscientific fashion generic 
value to characters which are known to be variable, often of slight 
moment and usually not concomitant. As Coulter & Rose have 
shown, Velaea DC. to which Drude, Nat. Pflanzenf. iii. Abt. 8: 
168 (1898) has referred these plants, must be referred to Arracacia. 
The first available name therefore is Tauschia Schlecht. to which 
Gray referred with good judgment his 7. terana, later made the 
type of Museniopsis. In this connection it is interesting to note 
that Coulter & Rose in 1888 in their Rev. N.A. Umb. 120 wrote 
with evident conviction, “ There is no doubt that our species that 
have been described under Deweya [including Drudeophytum| are 
the same generically as the Mexican Velaea, fie. Tauschia, as NOW 
7 ] and as such must bear the older name.” 
At present I am transferring to Tauschia only those species 
which have come particularly to my attention during this study, 
_ although I have examined most of the described species referable 
_ tothis genus. The groups of species, discussed above may be dis- 
_ §nguished, in general, as follows: 







