INTRODUCTORY EXPLANATIONS 
FIGURES 
A number of plants are illustrated by full-page plates (thirteen 
in number, showing fourteen species or varieties, from drawings by 
Mrs. C. D. Henline), exhibiting the whole plant reduced, with 
separate representation of a single head, series of bracts, a disk- 
flower and a rayflower. 
Most species are illustrated by smaller figures, 92 in number, 
representing drawings from the specimens, by Miss Evelyn G. 
Flynn, and Miss Else H. Seringhaus, and by the author. These 
figures are intended to indicate characteristic leaf-form and bract ; 
also characteristic habit. No adequate representation of the 
rays is attempted; and in certain species they have been wholly 
omitted. The rays would require drawing in the field to bring 
out their slight but interesting differences satisfactorily ; and the 
rays are of little importance in distinguishing species in the her- 
barium. The uniform lettering adopted for these figures includes: 
(a) Whole plant or large portion of it, to show habit. 
(6) Characteristic leaf-form ; with comparative reduction added, 
as 1 if represented natural size, or 1, $, etc. Usually the position 
of this leaf on the stem may be seen from figure a. 
(c) Characteristic bract ; usually not a lowermost nor an inner- 
most bract. 
Any other letters occurring are explained with the particular 
species. 
TERMINOLOGY 
Genus. An assemblage of somewhat closely-related species ; 
but itself of somewhat varying degrees of difference from other 
similar groups or genera. 
Subgenus. Not used. 
Section. A less definite subdivision of a genus, informal and 
permitting English name ; used to express a certain degree of nat- 
ural affinity, or to combine miscellaneous species for convenience. 
Species. A group of individuals indicating their common 
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