The present paper has at the outset briefly reviewed the previous work done on the
genus Cyrtomium Presl by Christensen1), Tagawa2) and Ching3) and then pointed out that
the present study, based on extensive material as citated under respective species, resulted
in recognizing 59 species for the genus, of which 42 are described for the first time.
However, it may be pointed out that, because of the frequent occurence of a series
of morphologically intermediate forms, it seems to be apparent that hybrids may be ram-
pant, especially among the species of the Subseries Fortuneana, and that a number of
clearly definable are here tentatively described as forms or varieties under the related
species, pending further haryological studies.
Geographically, the genus is almost exclusively confined to China and Japan, with one
outlying species, C. micropteron (Kze.) Ching, in Southern India and East Africa.
Cytologically, the genus so far studied by Manton1) and the present writer (un-
published) has revealed that the species of the Series Fortuneana are apogamous tri-
ploids, but it is believed that diploids may exist in the members of the Series Nephrole-
pioidea, for which study is now in progress.
Systematically, the genus Cyrtomium is no doubt very closely related to Polystichum
Roth, especially to the Sect. Achroloma Tagawa from which it seems to be directly
derived. According to the types of venation, pinnation of frond-end, and the margin of
the pinnae (i.e. whether it is entire or serrate), the genus may be divided into two
series, each with two subseries.
In the old Chinese medical books, Cyrtomium fortunei and its allies are said to be
a useful drug long used as antiseptics by the Chinese people.
