SOUTHERN CALIFORNIA ACADEMY _OF SCIENCES 13 
A Revision of the Western Mentzelias 
BY ANSTRUTHER DAVIDSON, M. D. 
The difficulties attending the determination of the Ment- 
zelias of the Genus Trachyphytum I thought might be wholly 
personal, but on looking over the herbaria of the University of 
California, Messrs. Parish and Brandegee, I have sufficient 
reason for thinking that other botanists have found their 
Investigation as unsatisfactory as I have. 
When at the British Museum and at Kew Gardens last sum- 
mer, I was generously aided in the examination of the speci- 
mens they possess. These had been examined by Urban and 
Gilg, when preparing their exhaustive monograph *‘ Mono- 
eraphia Loasacarum.’’ Many of the specimens were named 
according to their classification, and the collector’s herbarium 
number of many of the specimens quoted is given in the mono- 
eraph. The work of identification was thus rendered very easy. 
In the ‘‘Monographia Loasacarum’’ the authors have left 
M. micrantha, M. congesta and MM. aurea as we understand 
them, but all the others are grouped as varieties of M. albicaulis 
Douel. 
Five varieties are @iven: 
Var. a—Genuina Urban et Gile. is our M.-integrifolia Wats. 
Var. b—Veitchiana Urb. et Gile. is M veitchiana Kell and 
M. affinis Greene. 
Var. c—Gracilenta Wats. is M. gracilenta T. & G. 
Var. d—Jonesii Urb. et Gilg. New species from Yueea, Ariz. 
Var. e—Pectinata Urb. et Gilg. is M. pectinata Kell. 
To me this is no solution of our difficulties and while it may, 
lke some of the new religions, be very broad and accomodating, 
it is not exactly what is desired for scientific work. In some 
instances there is lack of consisteney in their labelling. Acro- 
lasia pinetorum, Ileller, is in one place classed as genuina, and 
in another as veitchiana. A. pinetorum, Heller is a very defi- 
nite species and bears no very elose affinity to any other. 
Elmer 3657, Acton, Los Angeles, labelled M. congesta, is 
obviously Acrolasia davidsoni, Abrams. The latter species is 
so distinet from the typical congesta, and its geographieal 
range is so different that one eannot very well understand its 
being’ overlooked. 
These differences of opimion may be but another proof of 
of the difficulties atendant on any attempt to meidly classify 
this genus. Whether my attempt to make more easy the seg- 
regation of the species is successful, time alone will tell. It 
has at least resulted in a better understanding of the distri- 
bution of the recognized species. 
