634 University of California Publications in Botany [Vol.8 



55. Pterygophora Rupr. 



Holdfast of stout, branched hapteres; stipe simple, solid, more or 

 less woody, containing mucilage ducts ; blade terminal, linear, without 

 distinct midrib but with central portion thickened ; sporophylls lateral 

 on both sides of the upper part of the stipe at the transition region, 

 long, and of continued growth ; sori on both sides of sporophylls and 

 on the terminal blade ; perennial, the stipe increasing in length and 

 in diameter through several years. 



Ruprecht, Bemerkungen, 1848, pp. 8 (64) and 14 (70) (nomen), 

 Neue Pflanzen, 1852, p. 17 (73) (description). 



Pterygophora was first proposed by Ruprecht in 1848, as above 

 mentioned, in connection with a study of the structure of the stipes 

 of some of the large Melanophyceae. A diagnosis of the whole plant 

 was deferred until 1852. No other species than the one then proposed 

 as the type, viz., P. calif omica, has been discovered since, and this one 

 seems to be in a state of specific equilibrium, as it varies but slightly 

 throughout its entire range of distribution. It was discovered by 

 Wosnessenski in the vicinity of Fort Ross, California, in 1840. It is 

 less specialized than Alaria. 



Pterygophora californica Rupr. 

 Plate 74 



Stipe terete below, flattened and somewhat constricted above at the 

 transition region, with distinct concentric rings shown in cross-section, 

 8-12 dm. (up to 2 m.) long, 2.5-4 cm. (up to 7 cm.) diam., giving rise 

 successively to elongated, blade-like sporophylls, pinnately arranged 

 in the transition region ; blade with mucilage ducts and with a slightly 

 thickened median, longitudinal band, forming a false midrib, linear, 

 6-9 dm. long, 6-10 cm. wide, fruiting annually then dying back and 

 regenerating ; sporophylls of the same general shape as the blade, but 

 smaller, stipitate, without median thickening, 12-18 maturing in a 

 season, then disintegrating, leaving only a scar on the stipe, new ones 

 meanwhile developing above ; sori occupying the basal half or more of 

 each sporophyll on both sides. 



Growing on rocks and on other large algae in the upper sublittoral 

 belt, largely on exposed coasts. From the southern end of Vancouver 

 Island to Lower California. 



