412°: STANDLEY: CHENOPODIACEAE 
This family is not an easy one for study, especially because of 
the great individual variation frequently found within a species. 
It is often extremely difficult to decide where specific lines should 
be drawn, consequently it will be many years before all American 
botanists agree upon a classification. Such a condition is not 
peculiar to the Chenopodiaceae, but it does seem more charac- 
acteristic of this family than of some of the closely related ones, 
such, for instance, as the Amaranthaceae, in which the species are 
clearly defined. 
The present notes are intended to explain some of the more 
important changes in nomenclature which the writer has found 
necessary, as well as to illustrate by citation of specimens the 
material upon which some of the new species are based. In the 
case of new species founded upon a single collection, no comments 
seem necessary, the basis of segregation being explained suf- 
ficiently by the keys. In the course of. the preparation of the 
account of the family, the writer examined, besides the material 
in the United States National Herbarium, all that in the Gray 
Herbarium and the herbaria of the New York Botanical Garden 
and the Missouri Botanical Garden. Certain material was lent, 
also, from the herbaria of the Field Museum of Natural History, 
the University of California, and Professor W. L. Jepson. | 
CHENOPODIUM L. 
In none of the genera of the Chenopodiaceae are the species 
quite so perplexing as in Chenopodium, particularly in the group 
of C. album L. and its allies. This applies not only to the species of 
eastern North America, which are mostly adventive from Europe, 
but also to the western ones, which are endemic. The chief char- 
acter relied upon for specific segregation has generally been leaf 
form, which, in any group of flowering plants, is seldom by itself 
a satisfactory criterion of species. In the present instance it is 
doubtless the best character available, at agente in the case of the 
European species. 
In Europe much attention has been devoted in recent years 
to a study of Chenopodium, a study based not,only upon large series 
of herbarium specimens, but also upon cultivated pedigreed plants. 
