The Genus Eritrichum in North America 
By WILLIAM F. WIGHT 
Although four different forms under this genus have been rec- 
ognized in North America, there seems to have been much mis- 
apprehension, in regard to some of them at least, as to their rela- 
tionship to the European £. xanum and to each other. A fruiting 
specimen of one of the Alaskan species not hitherto described 
has also recently been collected, making a complete description 
possible, and it is thought that the descriptions given below would 
therefore be desirable. The author wishes to express acknowl- 
edgments to Mr. Frederick V. Coville and Dr. J. N. Rose for 
criticisms and suggestions in the preparation of the paper, to Mr. 
F. A. Walpole for the drawings of the nutlets and to Professor 
Robinson, of the Gray Herbarium, for the loan of material. 
The North American species are separable into two main 
groups, the section Eueritrichium of DC.* with four species, £. are- 
toides, E. argenteum, E. Chamissonis and E. splendens, and a second 
section not before recognized with two representatives, 2. Howardi 
and £. elongatum. The first section has fruit with a toothed border 
which is characteristic of EZ. nanum, the type of the genus, figured 
by Gurke,+ while the two last named species have fruit with a mar- 
ginal ridge-like elevation. These are not referable to the section 
Amblynotus DC.t represented by a single species, Z. obovatum 
DC., which does not even appear to be congeneric with any of 
the species under consideration since it differs in having fruit with- 
out teeth or any trace of a marginal border, and is convex on the 
dorsal side instead of flat or with a slight central ridge, as is the 
Case with typical Eritrichum. 
ERitTricHuM Schrad. 
Eritrichum Schrad. Comment. Goetting. 4: 186, 1820, based 
on Myosotis nana Vill. 
Eritrichium Gaudin, Fl. Helv. 2: 4. 1828. 
* DC. Prodr. 10: 125. 1846. 
t Gurke, in Engler and Prantl, Die natiirlichen Pflanzenfamilien, 4%*: 108. f. 43. 
407 
