Stigonema minutum Hassall ex Bornet et Flahault (1887: 72)

Da Anunciação, Raylane R., Paulino, Jonatas M., Moura, Ariadne N., Laughinghouse IV, H. Dail & 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 : 22-23

Stigonema minutum Hassall ex Bornet et Flahault (1887: 72) ( Fig. 14J–N ).

Filaments creeping, entangled, uni- to multiseriate, erect, 15.3–25.03 µm wide. Branches T-like, not clearly distinguishable, uni- to multiseriate in apical young filaments. Sheath firm, smooth, 1.12– 3.3 µm wide, not lamellated, yellowish-brown to brown. Cells round, elongated, irregular-quadratic, irregular-rounded, 5.31–16.52 µm wide. Individual envelopes firm, smooth, brown. Cell content granulated, blue-green. Heterocyte spherical, semielliptical, sub-quadratic, in lateral or in intercalary portion, 3.62–15.48 µm wide, 6.13–11.05 µm long. Hormogonia numerous, developed in the apical branches, 11.23–15.67 µm wide, 18.91–33.53 µm long, 4–6 cells.

Habitat: —Soil; associated with Trichocoleus acutissimus and Gloeocapsopsis dvorakii . Rock; associated with Gloeocapsopsis dvorakii .

Studied material: — PEUFR55790 , PEUFR55812 , PEUFR55767 .

Figures

FIGURE 14. A–C. Scytonemataceae sp.; D–F. Stigonema corticola; G–I. Stigonema fremyi; J–N. Stigonema minutum. O–S. Mastigocladopsis sp.—O. details of the arrangement of the filaments; P. Apical cell; Q. Akinete; E–F. the filament details. Scale: 50 μm (D; G; J; O); 10 μm (to the others).