80 



Rhodora [Mat 



in Wales, for example (Carrington & Pearson, Hep. Brit. Exsic. 184), 

 which Pearson used for most of his illustrations, the leaves are distant 

 and often greatly reduced in size but show no evidence of falling away. 

 His other figures were drawn from specimens collected by Jack in 

 Baden (Gottsche & Rabenhorst, Hep. Europ. 198, 401); the first 

 was distributed under the name " Mastigobryum deflexum var. £ 

 flaceidum Nees" and the second under the name "M. deflexum $ 

 implexum." Both show caducous leaves to a greater or less extent 

 and also differ from the Welsh specimens in other respects. 



In 1912 Macviear 1 followed the example of Pearson and recognized 

 both "Bazzania tricrenata (Wahl.) Pears." and " B. triangularis 

 rears.," dating them from the year 1900. According to his account 

 B. triangularis "can generally be separated in Britain without diffi- 

 culty from B. tricrenata," and "the typical forms of the two plants 

 never grow in the same patch." He described two principal forms 

 of H. triangularis and a third, apparently less important, form. In 

 the first the leaves are mostly distant, never falcate, and usually 

 (but not always) acute, while the underleaves are oblong-quadrate 

 and entire; in the second the leaves are approximate, sometimes 

 falcate, and often two- or three-toothed at the apex; in the third 

 the leaves are narrow, nearly flat, and frequently three-toothed. 

 He brings out the additional fact that the cells of B. tricrenata are 

 24-30 [J. in diameter, while those of B. triangularis are only 16-25 [X. 

 but makes no allusion to the early falling away of the leaves. His 

 illustrations clearly represent the first of his three forms, which is 

 essentially like the Welsh plant figured by Pearson, while h's second 

 and third forms would agree better with Jack's Baden specimens. 



In 1914 Schiffner distributed specimens of Bazzania triangularis 

 (Schleich.) Lindb. and " B. tricrenata (Wahlenb.) Pears." in his Hep. 

 Europ. Exsic. 037-050 and commented on them in the thirteenth 

 series of his "Kritische Bemerkungen." 2 He expresses the opinion 

 that these species are distinct in Scotland, but connected by transi- 

 tional forms in the mountains of Central Europe. Under B. trian- 

 gularis he issued Scotch specimens, illustrating Macviear 's first 

 form, as forma laxa; French and Italian specimens, illustrating his 

 second form, as forma densior; and Bohemian specimens, representing 

 a new var. intercedens, stating, in regard to the last, that it might 



'Student's Handb. British Hepatics 317, 318. 1912. 

 2 Privately printed at Gottesberg, Silesia. 



