1918] Pennell, — A Plea for Aureolaria 137 
which is positive, the fact that the two plate-like lobes of the stigma 
ve fused, leaving as stigmatic areas only the lines of fusion on either 
side. But this condition is true, and also stages of evolution toward 
it are shown, in others of this tribe. There is a southwestern species 
which we have long been assured is a “Gerardia,” G. Wrightii A. Gray, 
in which the stigma is capitate. Having correlated characters, I 
consider the last a monotypic genus. To be required to retain it in 
an aggregate Agalinis would certainly make all definition that defines 
hopeless. 
If we accept as distinct genera Aureolaria and Agalinis we have for 
each excellent correlations of mostly positive characters; of habit, 
leaf, corolla-color, anther-awning (with one exception), capsule-shape 
and (of two types in Aureolaria) of seed. Moreover with one excep- 
tion, the specific range of parasitism is quite different. If we unite 
these, or place others with them, and then seek to limit our aggregate 
genus, we find our problem difficult and any result unsatisfactory. 
Of course genera can be built upon single characters, but the purpose 
of genera is the expression of kinship, not the arbitrary division of 
the field of-nature into categories of classification. 
Pardon so long a discussion. But I feel that misunderstanding 
frequently exists, because we can not or do not make our comparisons 
sufficiently broad. Frequently the cry is raised, and too often with 
justification, against the splitting of old genera into segregates — 
these apparently distinct for the area under consideration but well- 
merged by intermediate species elsewhere. More rarely, or at least 
less protested, is the opposite case, the joining of natural groups into 
aggregates which beyond the home-area are ill-defined or not defin- 
able. I hope that this paper has presented clearly enough one such 
case, and that for the future we can all agree in the use of the names 
Aureolaria and Otophylla. 
New York BOTANICAL GARDEN. 
t 
