DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM (BATRACHOSPERMALES, RHODOPHYTA) IN NORTH-AMERICA .6. SECTION-TURFOSA

Twenty-one populations of Batrachospermum section Turfosa from North A merica were compared to nine type and two historically important speci mens using multivariate morphometrics and image analysis. The protolog ues of six other infrageneric taxa were also compared. From this analy sis, six species are recognized worldwide: B. desikacharyi Sankaran, B . gombakense Kumano et Ratnasabapathy, B. keratophytum Bory de Saint-V incent [syn. B. vagum var. keratophytum (Bory de Saint-Vincent) Sirodo t, B. gulbenkianum Reis, and B. suevorum Kutzing nom. illeg.], B. sine nse Jao, B. turfosum Bory de Saint-Vincent [syn. B. vagum (Roth) C. Ag ardh and B. vagum var. undulato-pedicellatum Kumano et Watanabe], and B. vogesiacum F. G. Schultz ex Skuja [syn. B. vagum var, flagelliforme Sirodot, B. flagelliforme (Sirodot) Necchi]. These species are distin guished on the basis of carposporophyte-bearing branch cortication, se condary fascicle development, monoecy or dioecy, presence of spermatan gia on involucral filaments and monosporangia, and dimensions of trich ogynes and carposporangia. Peripheral cortication has been previously used to separate species in this section, but we observed that this fe ature is quite widespread in the section. Presence of indeterminate go nimoblast filaments has been reported for some taxa in section Turfosa , but no such structures were seen in any of the specimens examined. O nly B. keratophytum has been collected in North America, ranging from southwestern Greenland (64 degrees N) to Louisiana (30 degrees N).