THE THALLOSH HEPATICAE OV Tllli: JUAN FERNANDliZ ISLANDS 553 



Marchaiitiales. 



Rcboidiaccai'. 



Plagiochasina Lchm. & Lindenb. 



*i. P. rupcstrc (Forst.) Steph. Bull. Herb. 15oissier6: 783 (1898); EvANS, 

 Bull. Torrey Club 42: 277 f. i — 4 (1915)- — Syn. Aytonia riipestre Forst. Char. 

 Gen. Plant. 147 pi. 74 (1776). The species has a long synonymy. 



Damp or wet rocks, often in shade, below 500 m. (Fertile Dec. -Feb.). 



Masatierra: Pangal, waterfall at some distance from the water, 205 m. 

 (no. i); slope of Co. Damajuana, in forest (no. 2); O. Damajuana, steep slope 

 with forest, 345 m. (no. 3); B. Cumberland, vicinity of the colony, Skottsherg, 

 1908 (no. 4); S. slope of Co. Chumacera (no. 5). 



Masafuera: Q. de las Vacas, under Calystcgia (no. 6). 



Although P. riipestre is here reported from Juan Fernandez for the first 

 time it was collected by Skottsberg on Masatierra in 1908, as noted above, 

 the earlier specimens growing in admixture with Rcboulia JiemispJiaerica. The 

 writer has recently published a description of this variable and widely distributed 

 species, giving a full synonymy. 



Area of distribution: Mediterranean region of Europe, Asia and Africa; 

 the Atlantic Islands; Abyssinia; South Africa; Australia and New Zealand; New 

 Mexico and Arizona; Jamaica; Mexico; Brazil; Ecuador, south to Chile; Gala- 

 pagos Islands; Juan Fernandez. 



Reboulia Raddi. 



2. R. hemisphaerica (L.) Raddi, Opusc. Sci. Bologna 2: 357 (1818); 

 Stephani, 5. — Syn. Marc/ia?itui JionispJiaerica L. Sp. PI. 1138 (1753). The 

 species has a long synonymy. 



On rocks, below 500 m. (Fertile Feb.). 



Masatierra: B. Cumberland, vicinity of the colony, Skottsberg, 1908 

 (no. 40, cited by Stepiiani, 5). 



Masafuera: Between Q. de las Casas and Q. del Blindado, on rocks 

 among ferns (no. 7); cited also by Stephani, 5, from the vicinity of Q. de 

 las Casas. 



Most writers assign a wide range of variability to R. Jicmisphaerica and 

 regard the genus Reboulia as monotypic. 



Area of distribution: much the same as that of PlagiocJiasma riipestre 

 but even more extensive, reaching northern Europe, Asia and North America. 



