petals stand erect while the others are parallel to the tube, giving 
the flower the appearance of being somewhat bilabiate. This, 
however, is only in appearance as the petals are all the same size 
and shape. This condition does not obtain in all the forms, many 
being narrowly funnelform and some quite tubular. 
Greene depends chiefly upon the shape, pubescence, venation 
and insertion of the leaf for the separation of his species, giving 
little attention to the floral characters. To my mind no one char- 
acter or set of characters seems sufficient, and in many forms the 
flower offers a very excellent character whereby to distinguish 
the species. 
It might be pertinent to suggest that this genus, like some 
other genera of the Onagraceae, is in more or less plastic condi- 
tion and some of the forms not yet fully "set in their ways." It 
has more than once been asserted that the forms of Zauschneria 
are not constant and that a great part of the variation is purely 
environmental. It would certainly be a very interesting experi- 
ment to cultivate these diverse forms under identical conditions 
for a period of years to establish the truth or falsity of this con- 
tention. 
Before beginning the consideration of the species I propose to 
recognize, I wish to gratefully acknowledge the deep obligation 
I am under to all those who have helped me in any way, and 
especially to the following persons : Prof. H. M. Hall and his 
associates of the Department of Botany in the University of Cali- 
fornia, for the loan of the material in their herbarium. Miss Alice 
Eastwood, of the California Academy of Sciences, for the loan of 
material and valued MSS. notes. Prof. L. R. Abrams, of Stan- 
ford University, for the loan of material and notes and sugges- 
tions. Dr. O. E. Jennings, of Carnegie Museum, Pittsburgh, Pa., 
for the loan of material. Dr. Aven Nelson, of the University of 
Wyoming, for original descriptions. Profs. J. C. Nelson and M. 
E. Peck, of Salem, Oregon, for a specimen from their region. 
Prof. Philip Munz, of Pomona College, for the loan of material 
Mr. I. M. Johnston, of Upland, Calif., for material and sugges- 
tions. Mr. Frank S. Daggett, Director of the Los Angeles 
County Museum of History, Science and Art, for his aid in secur- 
ing much valuable material and for many privileges at the Mu- 
seum in connection with the study ; and to the many friends who 
have so generously contributed specimens from their collection* 
15 
