CONTRIBUTIONS FROM THE GRAY HERBARIUM OF HARVARD 
UNIVERSITY. 
New Serres. ~ No. XXXII. 
REVISION OF THE GENUS SPILANTHES. 
By ALBERT HANFORD Moore. 
Presented by B. L. Robinson, October 10, 1906. Received November 10, 1906. 
INTRODUCTION. 
Wuen this revision was undertaken, the genus Spilanthes was found 
to be in a very confused condition, and the work was greatly hampered 
by lack of abundant and authentic material ; a lack, however, which it 
was ina large measure possible to overcome through the great generosity 
of numerous botanists in different parts of the world. But for the pur- 
pose of further study and for the more intelligent determination of 
ranges a great deal of material of the genus should be collected. The 
genus has been so little understood that it seemed more than usually 
desirable to base information regarding the ranges merely on actual 
specimens or reproductions examined rather than on published ac- 
counts. For habitat the labels give almost no data, and except in a 
few cases there were not specimens enough to form satisfactory con- 
clusions as to the dates of flowering and fruiting, so that no mention 
of these subjects has been made. It is hoped, however, that such 
attention in the field will be accorded this interesting genus that the 
knowledge of all these matters may be supplied. 
The species have proved to be almost entirely lacking in constant 
technical characters, so that it has seemed artificial to maintain many 
of the earlier ones in an independent rank. The genus thus con- 
tains several complex groups of interrelated types, the study of a con- 
siderable amount of material of which shows them to intergrade very 
strongly with each other. It is certainly very undesirable to attempt 
to distinguish species upon the basis of mere leaf and habital varia- 
tions. Therefore in treating the genus it has been the plan to make 
the species stand for something definite, at least, so that they may 
represent an aggregation of variations more like each other than like 
