Desmidium graciliceps (Nordstedt) Lagerheim var. groenbladii C.Bicudo & Samanez, Bibliotheca Phycologica 68: 39, fig. 11. 1984.

(Fig. 9)

Cell 1.6 times greater in length than width, 43-48 × 23- 26 μm, 9-10 μm broad at the apex and 18-19 μm broad at the isthmus. Semicells pyramidal-truncated; straight apical margin; convergent undulated lateral margins with slight concave at the subapical region; rounded basal angles; shallow median constriction; open to linear median sinus; hyaline to light brown cell wall; axial chloroplast.

Material examined: BRAZIL, AMAPÁ, Macapá, Curralinho Lake, 03.VII.2007, C.B. Araújo (SP469218), 15.IV.2008, C.B. Araújo (SP469226), 15.VII.2008, C.B. Araújo (SP469228) .

Comments: this species has longer cells with broader apices than D. graciliceps var. graciliceps (Nordstedt) Lagerheim. Grönblad (1945) identified samples as D. graciliceps var. groenbladii as form “ gracilius ”, and later, Scott et al. (1965) and Förster (1969) identified their samples as var. “ gracilius ”. Despite neither the form nor the variety were ever formally proposed, Bicudo & Samanez (1984) designated specimens of this kind representative of D. graciliceps var. groenbladii Bicudo & Samanez.

Distribution in Brazil: Bahia (Oliveira et al. 2010); Pará (Scott et al. 1965, Förster 1969); São Paulo (Bicudo & Samanez 1984, 2016); Federal District (Leite & Senna 1992).