Ballantine D.L. and Ruiz H. 2010. Two new deepwater Peyssonnelia species, Peyssonnelia iridescens and Peyssonnelia gigaspora (Peyssonneliaceae, Rhodophyta) from Puerto Rico, Caribbean Sea. Phycologia 49: 537–544. DOI: 10.2216/09-88.1

Two new distinctive Peyssonnelia species are described from deepwater habitats in southwestern Puerto Rico. Peyssonnelia iridescens possesses a distinctive bluish iridescent fringe and forms loosely adherent blades up to 6.0 cm across. The crusts possess a Peyssonnelia atropurpurea-type vegetative organization. Tetrasporangia are cut off distally from apical perithallial cells and measure up to 53 µm wide × 135 µm long. Carposporangia measure 25–30 µm in their largest dimension and are formed in elongate nemathecia. Peyssonnelia gigaspora is variously coloured, tan to reddish, with obvious radial striations and reddish spots when living. The crusts are closely appressed to the substratum and normally measure up to 130 µm in thickness, but are occasionally 200 µm thick and possess the Peyssonnelia rubra-type vegetative organization. Tetrasporangia are ovate and extremely large, measuring up to 100 µm wide × 250 µm long, and differentiate from the proximal paraphysal cell, thus being situated in an intercalary position.