Morgan L. Vis

DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM (BATRACHOSPERMALES, RHODOPHYTA) IN NORTH AMERICA. 3. SECTION SETACEA1

Six populations of Batirachospermum section Setacea from North America were compared to eight type specimens using multivariate morphometrics and image analysis. From this analysis, four species in this section were distinguished worldwide: B. atrum (Hudson) Hartley [syn. B. gallaei Sirodot]; B. orrthostichum Skuja, B. sertularina (Bory) Bory]; B. diatyches Entwisle; B. androinvolucrum sp. nov.; and B. puiggarianum Grunow in Wittrock et Nordstedt (syn. B. angolense Welwitsch ex West et West, B. nigrescens Welwitsch ex West et West). Two of these species were found in North America: B. atrum in California and Texas and B. androinvolucrum in British Columbia, Washington State, and Alabama. The new species, B. androinvolucrum, is distinguished by having spermatangia restricted to one‐celled involucral bracts of the carpogonial branch.

Morphometric analysis of Batrachospermum section Batrachospermum (Batrachospermales, Rhodophyta) type specimens

Type and historically important specimens of 46 species and infraspecific taxa from Batrachospermum sect. Batrachospermum were examined. Of these, 48 specimens of 33 taxa were compared using multivariate morphometrics and image analysis. Nine species from the cluster analysis and one other species are recognised: B. anatinum, B. arcuatum, B. boryanum, B. carpocontorum, B. confusum, B. fluitans, B. gelatinosum, B. heterocorticum, B. pulchrum and B. skujae, B. ectocarpum is considered to be synonymous with B. anatinum, rather than with B. boryanum or B. arcuatum as has been proposed by previous authors. The illegitimately named species B. helminthosum Sirodot (non Bory) is referable to B. confusum as are B. crouanianum and B. fruticulosum. No varieties of B. gelatinosum could be supported and numerous taxa including B. pyramidale, B. densum and B. decaisneanum are synonymised within this species. The taxa in sect. Batrachospermum are separated on the basis of whether they are monoecious or dioecious, carpog...

Distribution and systematics of the freshwater red algal family Thoreaceae in North America

North American populations and type specimens of Thorea and Nemalionopsis were compared using multivariate morphometrics and image analysis. We continue to recognise the separation of the two genera based on spore-bearing branch-to-assimilatory filament length ratio and assimilatory filament density (≤0·3 and loose for Thorea and ≥0·6 and compressed for Nemalionopsis, respectively). Four species of Thorea were distinguished worldwide: T. hispida (syn. T. andina, T. lehmannii, T. ramosissima), T. violacea (syn. T. bachmannii, T. brodensis, T. gaudichaudii, T. okadae, T. prowsei and T. riekei), T. clavata and T. zollingeri. The former two species have variable branched, non-clavate assimilatory filaments, whereas the latter two have unbranched, clavate assimilatory filaments. Thorea hispida has copious secondary branches while T. violacea is sparsely branched. Thorea clavata is differentiated from T. zollingeri by having fewer monosporangia per cluster. Two of these species were found in North America: T. h...

DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM (BATRACHOSPERMALES, RHODOPHYTA) IN NORTH AMERICA. 4. SECTION VIRESCENTIA1

Thirty‐nine populations of Batrachospermum section Virescentia from North America were compared to eight type specimens and two historically important specimens using multivariate morphometrics and image analysis. From this analysis, two species are recognized: B. helminthosum Bory de Saint‐Vincent (syn. B. bruziense Sirodot, B. graibussoniense Sirodot, B. sirodotii Skuja ex Flint, B. testale Sirodot, B. virgatum Sirodot nom. illeg., and B. viride Sirodot) and B. elegans Sirodot (syn. B. coerulescens Sirodot nom. illeg.). In B. helminthosum trichogynes are cylindrical to slightly club‐shaped with few to no protuberances, whereas in B. elegans half to all of the trichogynes have one to three basal knobs or branches. None of the qualitative features previously used to separate species in this section were found to be of taxonomic value due to their universal presence; quantitative characteristics were highly variable and overlapped among specimens examined. Emended descriptions of both species are provided. Batrachospermum elegans was collected in northeastern U.S.A. and central Costa Rica, whereas B. helminthosum ranged from Nova Scotia to Louisiana and was collected in central Mexico, Costa Rica, and northwestern U.S.A. Batrachospermum julianum Arcangeli and B. transtaganum Reis, previously classified in section Virescentia, were observed to have twisted carpogonial branches and, therefore, should be placed in section Contorta. Sections Setacea and Virescentia of Batrachospermum differ in whorl size, ratio of carposporophyte height to whorl diameter, and trichogyne stalking; hence, we continue to recognize them as being distinct taxonomic entities as originally described.

DISTRIBUTION AND SYSTEMATICS OF FRESHWATER CERAMIALES (RHODOPHYTA) IN NORTH AMERICA1

Twenty‐five freshwater populations of Ceramiales were collected in North America, 24 of which were from the tropical rainforest region of Central America and the Caribbean. The streams tended to be moderate in mean current velocity (X̄= 23.3 cm·S−1) and maximum width (X̄= 6.3 m) but high in temperature (X̄= 23.1°C), pH (X̄= 7.9), and specific conductance (X̄= 320 μS·cm−1). Three Bostrychia species were restricted to the Caribbean islands: B. moritziana (Sonder ex Kütz.) J. Ag. (syn. B. cornigera Mont. and B. radicans f. moliforme Post), with ecorticate indeterminate axes, monosiphonous ultimate branches, and cladohaptera; B. radicans (Mont.) Mont. (syn. B. leprieurii Mont and B. rivularis Harv.), with ecorticate and polysiphonous axes throughout and cladophaptera; and B. tenella (Lamour.) J. Ag., with corticate indeterminate axes, monosiphonous ultimate branches, and peripherohaptera. Ballia prieurii Kütz. was found in Belize and Costa Rica and was characterized by rebranched determinate laterals, opposite branching, and long apical cells (X̄= 61 μm) and axial cells (X̄= 43 μm). Caloglossa leprieurii (Mont.) J. Ag. was localized in Puerto Rico while. C. ogasawaerensis Okam. was collected only in Costa Rica. The two species were separated by site of branching (midrib vs. margin) and blade width (X̄= 384 vs. 861 μm). Polysiphonia subtilissima Mont. from Florida and Jamaica had four pericentral cells, no cortication, rhizoids arising from pericentral cells, and branches initiated at trichoblast scars.

Distribution and systematics of Batrachospermum (Batrachospermales, Rhodophyta) in North America. 8a. Section Batrachospermum: Batrachospermum gelatinosum

Eighty-six populations of Batrachospermum gelatinosum were examined from throughout its known range in North America and were compared using multivariate morphometrics and image analysis. Morphological variability was as great in individual populations as that measured among locations. Populations pooled for each biome showed a north-south trend in whorl and carpogonium size. The mean measurements for the tundra were significantly smaller in whorl diameter and larger in carpogonium size than those for the coastal plain. B. gelatinosum is widely distributed in North America, having been collected from the north slope of Alaska and Baffin Island in the north to Texas and Louisiana in the south. In addition to the populations analysed, herbarium specimens from North America were examined and confirmed locations in 17 US states, four Canadian provinces and the Yukon territory were added. Three populations, two from the boreal forest (Newfoundland) and one from the deciduous forest (Rhode Island), were examine...

DISTRIBUTION AND SYSTEMATICS OF BATRACHOSPERMUM(BATRACHOSPERMALES, RHODOPHYTA) IN NORTH AMERICA. 6. SECTION TURFOSA1

Twenty‐one populations of Batrachospermum section Turfosa from North America were compared to nine type and two historically important specimens using multivariate morphometrics and image analysis. The protologues of six other infrageneric taxa were also compared. From this analysis, six species are recognized worldwide: B, de‐sikacharyi Sankaran, B. gombakense Kumano et Ratnasabapathy, B. keratophytum Bory de Saint‐Vincent [syn. B. vagum var. keratophytum (Bory de Saint‐Vincent) Sirodot, B. gulbenkianum Reis, and B. suevorum Kützing nom. Meg.], B. sinense Jao, B. turfosum Bory de Saint‐Vincent [syn. B. vagum (Roth) C. Agardh 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 distinguished on the basis of carposporophyte‐bearing branch cortication, secondary fascicle development, monoecy or dioecy, presence of spermatangia on involucral filaments and monosporangia, and dimensions of trichogynes and carposporangia. Peripheral cortication has been previously used to separate species in this section, but we observed that this feature is quite widespread in the section. Presence of indeterminate gonimoblast filaments has been reported for some taxa in section Turfosa, but no such structures were seen in any of the specimens examined. Only B. keratophytum has been collected in North America, ranging from southwestern Greenland (64°N) to Louisiana (30° N).

Distribution and systematics of Batrachospermum (Batrachospermales, Rhodophyta) in North America. 8b. Section Batrachospermum: previously described species excluding Batrachospermum gelatinosum

Sixty-two North American populations of seven previously described species belonging to Batrachospermum sect. Batrachospermum were examined and compared with appropriate type specimens using morphometrics and image analysis. All populations were similar to the respective type specimens in qualitative and quantitative characteristics, but the range of some morphological features has been extended. B. boryanum was the most abundant and widespread species, being collected in 34 stream sites from Newfoundland and British Columbia in the north to Georgia in the south. The other six species — B. anatinum, B. arcuatum, B. confusum, B. heterocorticum, B. pulchrum and B. skujae — were more localized and occurred in six or fewer streams. B. anatinum was restricted to Missouri, Arkansas and Virginia and B. arcuatum was collected in western North America from Alaska to Mexico. The distribution of B. confusum was disjunct, with populations occurring in Alberta, Quebec, Newfoundland, Maine and Missouri. B. heterocortic...