‘American Fern Journal 
Vol. 8 
APRIL-JUNE, 1918 No. 2 
Polystichum Andersoni and Related Species! 
WILLIAM R.. MAXON 
_ Among the genera of ferns probably none hae Heal 
regarded as subject to greater subspecific variation 
than Polystichum. How much of this supposed poly- 
eeesm is due to high variability actually existing 
Within the Species and how much to a failure to rec- 
ognize constant characters peculiar to like individuals 
from natural geographic areas is not altogether clear. 
ay clear, however, that some of the widely distributed 
types split up into readily recognizable forms, marked 
-Y good structural and vegetative characters, and that 
» uany instances what might, with scant material, 
4ppear a chance variant is in reality a well character- 
ie tent form throughout a given area, needing 
at be studied in the light of ample collections to 
— recognition as a sharply defined species. The 
Indian specimens, for example, had been char- 
a. vaguely as belonging to a few variable species; 
shee teal study of a. large amount of material has 
hl that for the most part the plants fall readily 
Ft the rather narrow limits of numerous species. 
their os mostly of restricted range; and ei? 
is ot fe nsuishing characters are sharply marked, 
in difficult to arrange them, on general resemblances, 
tals groups whose members have obviously had 
Publi a ithsonian 
Institution with the permission of the Secretary of the Smit 
‘ “Vontr, 1 se A 
: * - 8. Nat. Herb 2 25 Is. 2-9. 1909. 
INo, erb. 13: 25-39. pls. : lay 6, 
1948 j 1 of the JOURNAL (8: 1-32, Plates 1 and 2) was issued May 
33 
