Streptostemon sp.

Da Anunciação, Raylane R., Paulino, Jonatas M., Moura, Ariadne N., Iv, H. Dail Laughinghouse & Gama, Watson A., 2024, Morphometric Characterization And The First Taxonomic Synthesis Of Terrestrial Cyanobacteria From The Atlantic Forest In Northeastern Brazil, Phytotaxa 646 (1), pp. 1-31 : 26-27

Streptostemon sp. ( Fig. 16F–I ).

Filaments in fascicles erect, 10.69–15.09 µm wide. Sheath firm, (0.82) 1.13–2.82 µm wide, 1–2 lamellae, hyaline to brown. Trichomes with tolypothricoid branches in apical portion and usually scytonematoid geminate branches, not constricted. Apical cell rounded. Cells isodiametric to short, 6.29–11.53 µm wide, 4.53–10.78 µm long, ratio l/w = 0.83. Cell content homogenous, blue-green. Heterocyte elliptical, semielliptical or short, 6.25–11.36 µm wide, 5.02– 10.11 µm long, in basal or intercalary position. Necridia present. Hormogonia up to 12 cells, constricted.

Habitat: —Rock.

Notes: —This morphotype differs from other Streptostemon species by forming dense, erect fascicles that resemble Dapisostemon and usually scytonematoid branches

Studied material: — PEUFR 55781

Figures

FIGURE 16. A–E. Kryptousia sp.2; F–I. Streptostemon sp.; J–M. Tolypothrix rechingeri. Scale bar: 50 μm (A; G); 10 μm (to the others).