64 Rhodora [APRIL 
lateriflora and S. epilobiifolia are nearest the ancestral branch of the 
phylogenetic tree (diagram 1). Both are very wide-spread in distri- 
bution. According to the diagram, as I have conceived the situation, 
they represent the first forks of the tree, and both have given rise 
to groups showing the character in question. Further, in a hasty 
review of nutlet-characters of the other genera of the Labiatae, it 
appears that the character referred to is absent. "This is another 
justification for believing it is of more recent development. 
The first division was taken up by Gray, later adopted by Briquet 
and is now in use by authors of the larger manuals in this country. 
Briquet introduced names for these divisions or sections. "The section 
Scutellariopsis should be extended to include at least two more North 
American species. Hitherto Scutellaria nervosa has been classed as 
our sole representative of this group. Yet it is difficult to understand 
why 5. parvula, the achene of which has a conspicuous band, amazing 
in its constancy, should be left out. Here too we should place the 
S. angustifolia group, one species of which has nutlets with wings 
rivaling even those of S. nervosa. 
The present status of the work and the limited area covered do not 
justify the grouping of the species of the genus into sections. It is 
hoped that later a survey of the world representatives may be made, 
at which time such sectional characters may be properly adjudged. 
It is hoped also, that a study of the immediately related genera may 
be taken up, following the more critical reproductive characters. 
The arrangement of species given below follows a more or less 
natural system. As arranged, numbers 1, 2 and 3; 4 and 5; 6, 7, 8, 
9, 10 and 11; 12, 13, and 14; and 15, 16, 17, 18, 19, 20 and 21, form 
fairly well defined groups. It will be seen that they do not agree 
with treatments given by other students of the group. The fact 
that militates against this kind of grouping, of course, is that it 
indicates an impossible linear evolution. True relationships are 
better shown in the tree (diagram 1). 
There remains to say a word or two upon the acceptance of nutlet- 
characters as a basis for the separation of sections. This can best 
be brought out by means of an example: Perhaps one of the best- 
marked groups of species, the interrelations of which are shown by 
nutlet-characters, is the series consisting of S. lateriflora, S. galeri- 
culata and S. epilobiifolia. All three have canary-yellow achenes 
which are not duplicated elsewhere in the genus. Of these three S. 
galericulata (I am using this Old World species for purposes of illustra- 
