THE MOONWORT AND ITS ALLIES. 63 
reaches only to the base of the fertile. The latter varies 
in size from a short stalked division bearing one or two 
sporangia to a spike two inches in length.” Mr. Eaton 
writes me that ¢excbrosum can always be distinguished 
from its allies by the notch in the tip of the sterile portion 
and by the spores which are nearly twice as large as 
those of szimplex. The plant’s small size and variable 
nature have caused it to be regarded as a variety of B. 
simplex also. 
Tenebrosum grows on the borders of maple swamps. 
Where the earth is deeply covered with leaves, many 
specimens are never able to reach,the light and air, but bear 
fruit, nevertheless. Thus far it has been reported from 
Vermont, New Hampshire, Massachusetts and New 
York. It is likely to be found elsewhere within the 
range of the other small Botrychiums. In some spots, 
two hundred and fifty specimens have been collected in 
anhour. Our illustration was made from specimens col- 
lected by Mr. Eaton. 
The name of the genus is derived from a Greek word 
meaning a bunch of grapes and was given to this family 
in allusion to its clustered spore-cases. There are twenty- 
five or more species, widely scattered on the globe. In 
America, they are exceedingly variable and present some 
puzzling questions to the student. ‘Judging from size 
and external appearances alone,” writes Prof. Under- 
wood, “a regular gradation of forms might be arranged 
from the most diminutive undivided fronds of B. semplex 
to the largest of B. Virginzanum. 
