American Species of Marchantia. ' 207 



In 1899 Stephani^ published his monograph on Marchantia in 

 the first volume of his Species Hepaticarum. He describes 

 eighteen species in all from America, six of which are confined 

 to North America and eight to South America. Of these 

 eighteen species M. Elliottii of Dominica and M. caracensis of 

 Venezuela and Mexico are described as new, while M. cepha- 

 loscypha Steph. (1883), originally described from New Zealand, 

 is quoted from Chile and Patagonia. He accepts Schiffner's 

 reduction of M. cartilaginea to synonymy but maintains both 

 M. brasiliensis and M. oregonensis as valid. Under M. tabularis 

 he cites M. Berteroana as a synonym (on the authority of 

 Schiffner) but gives no American localities. Under M. domin- 

 gensis he gives M. inflexa as a synonym and states further that 

 the American stations for M. linearis (as given in the Synopsis) 

 belong to M. domingensis instead. He includes M. Dillenii 

 among the synonyms of M. chenopoda and considers that 

 M. peruviana and M. Notarisii are very close to this species and 

 may be merely forms of it. Two species recognized by the 

 Synopsis, M. quinqueloba and M. pusilla, he gives up altogether, 

 because they were based on fragmentary specimens, and he makes 

 no mention whatever of M. fl ah ell at a. 



If M. Berteroana is reinstated as an American species and 

 if M. flabellata is added, Stephani's total of eighteen species 

 would still be maintained, even if M. brasiliensis and M. oregon- 

 ensis are considered synonyms. It will be seen that this total is 

 scarcely different from the total of sixteen species given in the 

 Synopsis Hepaticarum. The writer hopes to show, however, that 

 these numbers are much too high and that further reductions to 

 synonymy are necessary. In his opinion there are only nine 

 species based on characters which seem trustworthy, and it is 

 possible that two of these will not be considered distinct when 

 they become more fully known. There remain five species which 

 are doubtful, either because the published descriptions are incom- 

 plete or because the original material is immature or fragmentary. 

 Two of these, as noted above, are discarded altogether by 

 Stephani, and it is probable that the other three deserve the 

 same fate. The doubtful species, however, will be alluded to 

 briefly at the close of the paper. 



^ Bull. Herb. Boissier 7 : 383-407, 518-533- 1899. 



