66 



THE FERN BULLETIN 



carved such genera as V it t aria, Antrophyum, Taenitis, 

 and others, in fact Hooker has suggested that it would 

 be well to make two genera by combining Vittaria, 

 Taenitis and Drymoglossum placing in one the species 

 with sori close to the margin and the other those with 

 sori remote from it. The principal reason given for 

 separating Drymoglossum from Taenitis is that in the 

 former group the fronds are dimorphic. 



Including the two American species, there are now 

 but nine species in the genus Dfymoglossum. The 

 seven Old W orld species are found in India, China, 

 Japan and in the adjacent islands. The species, car- 

 nosum, which we illustrate, is found in China and 

 Northern India, and extends to the Philippines where 

 the plant from which the illustration was made, was 

 collected by D. Le Roy Topping. 



Drymoglossum carnoswm is an attractive little plant 

 with a very slender and wide creeping rootstock which 

 gives off the small, entire, oblong sterile fronds at in- 

 tervals of an inch or more. The fertile fronds are 

 very different from the sterile, being two or three 

 times as long and very narrow. The sterile fronds are 

 barely stalked but the fertile have decided petioles. 

 The sporangia are borne in a dense continuous line 

 midway between the margin and the midrib and when 

 young are covered with peltate scales. Both sorts of 

 fronds are quite thick and leathery as befits a species 

 exposed to tropical drouth. It is interesting to note 

 that the fertile and sterile fronds are not produced in- 

 discriminately, but that each set is produced at a 

 definite time in the life cycle. Even in species of ferns, 

 in which we commonly discern no structural differ- 

 ence between fertile and sterile fronds, there is usually 

 to be distinguished a seasonal difference, the fertile 



