Benedict : The genus Ceratopteris 469 



Type from Ceylon. 



The Old World material appears to be all alike in sporangial 

 characters. In leaf-form there is considerable variation, and prob- 

 ably also in habit and habitat, but the information at hand does 

 not furnish any clue for the separation of the various forms as 

 species. Linnaeus recognized two species, Acrostichum siliquosum 

 and A. thalictroides, both based on Ceylon material and both forms 

 which can be identified with material of recent collections, but it is 

 not clear that they are more than seasonal variations of the same 

 plant, or perhaps modifications induced by adaptations to different 

 habitats. Mr. R. S. Williams, who has collected the siliquosa form 

 in the Philippines, tells me that he found it in grassy hollows, 

 forming small clumps not very dissimilar in appearance to the 

 grass itself, and in situations in which it may not have been sub- 

 merged at any time. Such a plant would perhaps lend itself more 

 readily to variation in the moisture available than the strictly 

 aquatic American plants, so that its wider distribution and variation 

 are not so anomalous as might first appear. 



It appears to be generally distributed in the Old World tropics. 

 From the material seen the following distribution may be recorded : 

 Japan, Formosa, the Philippines, Himalayan region to Ceylon, 

 Malay Peninsula, Java, Andaman Islands, Queensland (Moreton 

 Bay), Madagascar, and Jamaica (?). As already noted some strik- 

 ing forms are included which probably deserve separation. I 

 have not seen any West African material {C. cornuta) so do not 

 know whether this should also be included in the thalictroides 

 complex or not. The reference to Jamaica is based on a specimen 

 in the National Herbarium * which agrees almost exactly with 

 some of Mr. Williams' Philippine material. It is, however, with- 

 out data other than that of a stock printed label, no time or place 

 of collection being given, so that it is possible that the plant is 

 not really Jamaican. 



2. Ceratopteris Lockharti (Hook. & Grev.) Kunze, Linnaea 



23 : 241. 1850 



Parkeria Lockharti Hook. & Grev. Icon. Fil. pi. 97. 1828. 



(In footnote.) 



*The label heading reads as follows: Flora Jamaicensis | No. 124. Coll. John 

 Hart, Supt. Govt. Cinchona Plantation, | Gordon Town, Jamaica, W. I. | Ceratop- 

 teris thalictroides Brong. 



