Cosmarium cf. bioculatum Brébisson ex Ralfs

Adam, Chaidir, Kenins, Alex & Prabowo, Danang A., 2025, Diversity and new records of desmids (Zygnematophyceae, Charophyta) in Central Kalimantan, Indonesia, Phytotaxa 691 (2), pp. 125-150 : 133

Cosmarium cf. bioculatum Brébisson ex Ralfs

Croasdale & Flint 1988, p. 55, pl. 32, figs 10–13.

Fig. 4b

Comments: We have designated this species as Cosmarium cf. bioculatum by virtue of the size range of our specimens being within the limits of the quoted dimensions of this species. Coesel & Meesters (2007) rated this desmid as meso-eutrophic and found in slightly acidic to alkaline waterbodies. However, Croasdale & Flint (1988) rated it as oligo-mesotrophic and found in moderately acid to occasionally lime-rich habitats.

Distribution: Probably cosmopolitan but the distribution of this species is not well understood due to it being confused with other similar Cosmarium species see Coesel & Meesters (2007).

Figures

FIGURE 4. Cosmarium: (a) C. angulosum Brébisson, (b) C. cf. bioculatum Brébisson ex Ralfs, (c) C. difficile var. dilatatum O.Borge, (d) C. geminatum f. ornatum Behre 1956, (e) C. granatum Brébisson ex Ralfs, (f) C. margaritatum var. quadrum Willi Krieger, (g) C. obsoletum (Hantzsch) Reinsch, (h) C. cf. obtusatum (Schmidle) Schmidle, (i) C. pseudopyramidatum P.Lundell, (j) C. regnellii Wille, (k) C. striolatum (Nägeli) W.Archer, (l) C. cf. sublatereundatum West & G.S.West, (m) C. cf. subspeciosum var. validius Nordstedt.