Closterium cornu var. minus Irénée-Marie (1952: 7)

Ramos, Geraldo José Peixoto, Bicudo, Carlos Eduardo De Mattos & Moura, Carlos Wallace Do Nascimento, 2018, Some new, rare and interesting desmids from bromeliad phytotelmata in Brazil, Phytotaxa 346 (1), pp. 59-77 : 60-61

Closterium cornu var. minus Irénée-Marie (1952: 7) ( Figs 1–2 )

Cells semilunate, 9 to 11 times longer than wide, slightly curved, not inflated in the median region; poles acuminatetruncate; cell walls smooth; chloroplast axial, pyrenoids 2 to 4 in series. Cell dimensions: 44–59 μm long, 4–6 μm wide, 2–3 μm apices.

Material examined: BRAZIL, Bahia, Santa Teresinha, Serra da Jiboia. 14-I-2015, G. J. P. Ramos et al. s/n ( HUEFS 224653), 18-VII-2015, G. J. P. Ramos et al. s/n ( HUEFS 224680), 11-IX-2015, G. J. P. Ramos et al. s/n ( HUEFS 224697), 20-XI-2015, G. J. P. Ramos et al. s/n ( HUEFS 224710)

Habitat: bromeliad tanks ( Alcantarea nahoumii ); water temperature 26.5 (± 2.8 ºC). pH 5.9 (± 0.6). conductivity 0.25 (± 0.19 mS. cm-1). total dissolved solids 0.13 (± 0.09 ppt). dissolved oxygen 6.5 (± 2.3 mg.L- 1).

Notes: Closterium cornu var. minus is a rare taxon, with only one record for the type locality (Québec, Canada) ( Irénée-Marie 1952). The variety identified here differs by having smaller cell dimensions (up to 60 μm) than those generally reported for the typical variety (95–190 μm) ( Prescott et al. 1975). All specimens from the phytotelmata had cell dimensions similar to C. cornu var. minus . This variety was considered as occasional in the bromeliads from Serra da Jiboia ( Table 1).

Figures

FIGURES 1–25. Closterium cornu var. minus LM (1, 2); Cosmarium amoenum var. jiboensis: LM (3–6); SEM (7–8), ventral view (3–4, 7), lateral view (44) apical view (46–48) and detail of cell wall with granules surrounded by pores; C. bahianum: LM (9–12); SEM (13), ventral view (9–10, 13), lateral view (11) apical view (12); C. elegantissimum: LM (14–16); SEM (19), ventral view (14–15, 17–19), apical view (16); C. scrobiculosum: LM (20–23); SEM (24–25), ventral view (20–21, 25), lateral view (22) apical view (23–24). Scale bar 10 μm (1–7, 9–24), 5 μm (8, 25).