Abstract:

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.