1917] Butters,— Studies in Ferns — Botrychium 207 
thence into the South American Andes, in India (A. pectinatum Pr.) 
and in Abyssinia (A. Schimperi Mong., apparently the closest relative 
of our A. asplenioides). With these exceptions they are entirely 
wanting from the tropical regions, and from the southern hemisphere. 
II. BOTRYCHIUM VIRGINIANUM AND ITS AMERICAN 
VARIETIES. 
In 1915 Fernald and St. John ! called attention to the fact that 
Botrychium virginianum about the Gulf of St. Lawrence differs from 
the more southern typical plant in several respects. They identified 
this form with Botrychium virginianum var. europaeum Angstrém, 
arare fern'of Scandinavia, Russia, and central Europe. A re-examina- 
tion of all the North American and European material of this species 
in the Gray Herbarium indicates that the actual condition is somewhat 
more complex. 
In this examination particular attention has been paid to the char- 
acter of the sporangia and of the ultimate segments of the fertile frond 
which bear the sporangia. 
Each of the varieties has, indeed, its own characteristic sterile frond, 
but the attempt to distinguish them on this ground is unsatisfactory 
in view of the slight and often scarcely describable differences between 
the fronds of the different varieties, and the very considerable indi- 
vidual variation within the same variety. 
Typical Botrychium virginianum (L.) Sw. has a sterile frond of thin 
texture with the pinnules lanceolate, deeply pinnatifid or nearly pin- 
nate, and the ultimate segments oblong or lanceolate and scarcely 
or not at all spatulate. The ultimate segments of the fertile shoot are 
narrow (0.25-0.5 mm.) and thick, and in dried specimens appear nearly 
opaque. The mature sporangia are dark in color, varying in different 
plants from a moderately dark yellow brown to almost black. As 
in all the species of Botrychium, they vary considerably in size, the 
largest measuring 0.5-0.8 mm. in length and somewhat less in width.” 
1 Fernald, M. L., and St. John, Harold, The Occurrence of Botrychium virginianum var. 
europaeum in America. Ruopora, xvii. 233 (1915). 
2 The measurements of sporangia given throughout this discussion of Bolrychium virginianum 
and its varieties, are all taken from large fully developed sporangia. Smaller sporangia are 
always mingled with the large ones, and these vary in size in the respective species i ah call 
ally with the larger ones. 
