Riccia Beyrichiana and Riccia dictyospora 



By Marshall A. Howe 



In the course of some remarks at the meeting of the Torrey 

 Botanical Club held on December u, 1900, the writer made al- 

 lusion to the probable rediscovery at Athens, Georgia, by Mr. R. 

 M. Harper, of Riccia Beyrichiana — a species which is alleged to 

 have been discovered in this country about seventy years ago by 

 Herr Beyrich and has of late been a subject of considerable doubt 

 inasmuch as nothing apparently like it had been met with since. 

 It was our intention, as expressed to some at the time, to secure, 

 if possible, a portion of Beyrich's original plant before publish- 



• * 



ing any notes on Mr. Harper's specimens, in order that the 

 determination might not rest upon description alone. In the 

 original description nothing at all is said of the spores, from which, 

 in this genus, important specific characters are now drawn. Three 

 years ago, Herr Franz Stephani gave a new diagnosis of the species, 

 including an account of the spores, but this description was in a 

 • few respects somewhat out of harmony with Mr. Harper's plants 

 and increased the desire on our part to see the specimens of Bey- 

 rich's own collecting. A loan of the desired original from the 

 Lindenberg herbarium, now preserved in the Naturhistorisches 

 Hofmuseum at Vienna, has recently been obtained through the 

 courtesy of Dr. A. Zahlbruckner. And a careful comparison of 

 Beyrich's plant with that of Mr. Harper has led to the unexpected 



conviction that the two plants are absolutely distinct from each 

 other. 



Some further reference to the brief history of Riccia Bey- 

 richiana may be of interest at this point. The species was originally 

 described in Lehmann's " Novarum et minus cognitarum Stir- 

 pium Pugillus Septimus," published in Hamburg in 1838. Like 

 several other parts of this work, the seventh Pugillus contains 

 the diagnoses of numerous new Hepaticae, diagnoses which are 

 commonly ascribed to the joint authorship of Lehmann and 

 Lindenberg though it is occasionally suspected that Lindenberg 



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