FLORA OF THE GALAPAGOS ISLANDS. 87 



RiNODiNA, Mass. 



R. MAMiLLANA, Tuck. Proc. Am. Acad. vii. 226 (1866), & xii. 174. — 

 GA.LAPAGOS Ids.: Hassler Exp. \_Hill']. Further distrib. Oahu, 

 Hawaiian Ids. 



ROCCELLA, DC. 



The most striking feature of the maritime lichen flora of the 

 Gahipagos Islands as well as of the west coast of America from 

 California southward is the abundance of species of Iioccella of which 

 very fine specimens were collected by Messrs. Snodgrass & Heller. 

 In most herbaria the Roccellae of this region are somewhat vaguely 

 placed under the species II. fuciformis and R. tinctoria, the com- 

 planate forms being referred to the former and the more or less terete 

 forms to the latter. The excellent Monographia Roccelleorum of 

 Darbishire, Stuttgart, 1898, affords the means of a more satisfactory 

 determination. The separation of Dendrographa and Raccellaria from 

 Roccella on the structure of the cortex is well founded. All the 

 specimens of this group collected by Messrs. Snodgrass & Heller belong 

 to the genus Roccella proper. 



R. PEKUENSis, Darb. Bull. Herb. Boiss. v. 763 (1897), & Monogr. 

 Rocc. 47, t. 18, 19, f. 83-88 (1898). R. Moiitagnei, yar. peruensis. 

 Kremph. Verb. Zool. Bot. Gesell. Wien, xxvi. 443 (1876). R. fuci- 

 formis, C. E. Cuumiings in Rob. & Greenm. (1), 149, not Ach. — 

 Albemarle Isl.: B'lur. Bakrington Isl. : Snodgrass & Heller. 

 Charles Isl. : Banr. Chatham Isl. : Snodgrass & Heller. Dun- 

 can Isl. : Snodgrass & Heller. Gardner Isl. : Snodgrass & Heller. 

 Hood Isl. : Banr; Snodgrass & Heller. Tower Isl. : Snodgrass & 

 * Heller. A considerable number of specimens were collected, none, how- 

 ever, with apothecia. The yellow basal filaments described by Darbi- 

 shire are present in this species, which grows on shrubs. The specimens 

 are larger and broader than the figures of this species in Darbishire 

 and some resemble more closely his figure of R. portentosa, t. 8, f. 32. 

 It may be questioned whether that figure really belongs to R. portentosa. 

 In all specimens having this habit there were present the yellow base and 

 Jignicolous habitat which indicate R- peruensls. 



R. portentosa, Darb. Ber. Deutsch. Bot. Gesell. xv. 4 (1897), Sc 

 Monogr. Rocc. 29, t. 7-1 1 , f. 27-41 (1898). R. tinctoria, var. portentos<u 

 Mont, in Gay, PI. Chili, viii. 841 (1852). — Barrington Isl.: May, 

 1899, Snodgrass & Heller. Gardner Isl. : May, 1899, Snodgrass &. 



