Scytonema guyanense Bornet & Flahault (1888: 94) (Fig. 13A–C).

Filaments entangled, 13.20–54 µm wide. Sheath firm, 1.3–2.64 µm wide, non-lamellated or with 1 lamella, slightly ornate, hyaline to brown. Trichomes cylindrical, false geminate or single branched, constricted or not. Cells cylindrical isodiametric or short, 6.16–15.61 µm wide, 3.94–14.29 µm long, ratio l/w = 0.70. Cell content homogenous, pale green. Heterocyte cylindrical, isodiametric, elliptical, or short, 12.3–17.57 µm wide, 4.75–19.88 µm long, in intercalary position. Necridia present. Hormogonia constricted, with intercalary elliptical heterocyte, cell sub-quadratic to short.

Habitat: —Soil covered by moss.

Studied material: — PEUFR55791