CONTRIBUTIONS FROM THE GRAY HERBARIUM OF HARVARD 
UNIVERSITY, NEW SERIES, NO. XX. 
By B. L. Roprnson. 
Presented March 13, 1901. Received March 16, 1901. 
I, — SYNOPSIS OF THE GENUS MELAMPODIUM. 
In the following key to Melampodium the genus is limited as by Ben- 
tham and Hooker in their Genera Plantarum and by Hoffmann in Engler 
& Prantl’s Natiirlichen Pflanzenfamilien. It will, therefore, be unneces- 
sary here to reproduce the generic description or give generic synonymy. 
The key is based chiefly upon the material which has accumulated in the 
Gray Herbarium, including*the recently acquired Klatt collection and 
some borrowed material from the U. S. National Museum. The writer 
has also in connection with this work been kindly permitted by Mr. 
Casimir de Candolle to examine and trace the types in the Prodromus 
Herbarium. Much difficulty has been experienced in giving the species 
a natural sequence, and after many efforts the hope of securing such an 
arrangement has been abandoned. The employment of pubescence in 
grouping the species of this genus is new and appears to yield more satis- 
factory results than an implicit reliance upon the fructiferous bracts. 
The latter, as is well known, often surpass the achenes, forming above 
them a cup or hood. This hood is often pointed dorsally at the summit 
and the point may be recurved or spirally coiled. Unfortunately, how- 
ever, these features, the hood and its appendage, show too great varia- 
bility in certain nearly related forms, such as M. sericeum and its 
varieties, to yield diagnostic characters of the first rank. However, the 
presence or absence of a hood can usually be determined readily, and 
the two sections Humelampodium and Zarabellia may coriveniently be 
retained. 
Bentham and Hooker, 1. c., estimated the species at eighteen, and 
Hoffmann, 1. c., accords twenty-five species to the genus. It will be 
seen, however, that this number can, with our present knowledge, be 
somewhat increased. The genus reaches its greatest development in 
Mexico, where, if we include Lower California and Central America, no 
less than thirty-one species occur. Of these species three reach the 
southern United States (one merely as an introduction), two are found 
‘. 
