Phormidesmis communis Raabová, Kovacik, Elster & Strunecký, 2019

Raabová, Lenka, Kovacik, Lubomir, Elster, Josef & Strunecký, Otakar, 2019, Review of the genus Phormidesmis (Cyanobacteria) based on environmental, morphological, and molecular data with description of a new genus Leptodesmis, Phytotaxa 395 (1), pp. 1-16 : 12

Phormidesmis communis Raabová, Kovacik, Elster & Strunecký , sp. nov. ( Figs 1J–N , 2B , 6C )

Description: —Filaments straight or slightly curved, solitary or entangled, with one or two trichomes per sheath. Filaments pale blue-green, constricted at the cross-walls. Sheath colorless, thick, sometimes narrowed towards the ends, mucilaginous. Filaments 1–2.5(3) μm wide. Cells are 1–3(3.5) μm long. Cells are barrel-shaped or shorter than wide, occasionally longer than wide. Central granules are present in cells. Nodi are rarely present on filaments in old cultures, or they are falsely pseudobranched. Apical cells are rounded without calyptra.

Habitat: —Subaerophytic in soil crusts, on bones and in epilithon in lakes; probably distributed worldwide.

Type: —Strain AB 11-10 is held in the Culture Collection of Autotrophic Organisms at the Institute of Botany AS CR, Třeboň, Czech Republic as item no. 1105.

Figures

FIGURE 1. Microphotographs of different strains that illustrate the morphological variability of four species of the genus Phormidesmis: A–E P. nigrescens, F–I P. priestleyi, J–N P. communis, O–T P. arctica, and U–Z Leptodesmis paradoxa. Scale bar = 10μm.

FIGURE 2. Drawings of four species of the genus Phormidesmis: A—P. arctica, B—P. communis, C—P. priestleyi, D—P. nigrescens. Scale bar = 10μm.

FIGURE 6. Shape of colonies. A—Leptodesmis paradoxa (6 weeks old), B—Phormidesmis arctica (3 weeks old), C—Phormidesmis communis (6 weeks old), D—Phormidesmis nigrescens (3 week old), E—Phormidesmis nigrescens (9 weeks old), F—Phormidesmis priestleyi (6 weeks old).Arrow indicates the brownish color of colonies which can be commonly found in natural populations under high light.