Cosmarium amoenum var. jiboensis G.J.P.Ramos, C.E.M.Bicudo & C.W.N.Moura, 2018

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 : 61

Cosmarium amoenum var. jiboensis G.J.P.Ramos, C.E.M.Bicudo & C.W.N.Moura var. nov. ( Figs 3–8 )

Cells 1.6–1.7 times longer than wide, deep median constriction with a linear, closed sinus, oblong in apical view, elliptic-oblong in lateral view; semicells semicircular, with rounded basal angles, slightly convex lateral margins, rounded apical angles, apical margin slightly convex to subtruncate; cell wall granulate, granules arranged in vertical series in the basal region of the semicells, sometimes in double rows, granules arranged in transverse series in the apical region, 3–5 pores surrounding the granules (SEM view); chloroplast with 2 pyrenoids; cells 44–47.5 μm long, 26.5–28 μm wide, 10–12 μm isthmus.

Holotype: material numbered ( HUEFS 224658 !) deposited at Herbário da Universidade Estadual de Feira de Santana , population partially illustrated here in LM ( Figs 3–6 ) and SEM ( Figs. 7–8 ).

Paratypes (here designated): HUEFS 224676, HUEFS 224702, HUEFS 224718 (Herbário da Universidade Estadual de Feira de Santana, Feira de Santana, Brazil)

Type locality and habitat: Collected at “Serra da Jiboia” Santa Teresinha, Bahia state, Brazil. 12° 51’ 6.6” S, 39°28’ 35.5” W. Sample collected by G. J. P.Ramos, C. W. N. Moura and M. A. Santos ( HUEFS 224658) on 14 January 2015. Cosmarium amoenum var. jiboensis occurred in samples collected in bromeliad tanks ( Alcantarea nahoumii ); T 27.5 (± 2.8 ºC). pH 5.9 (± 0.4). C 0.25 (± 0.18 mS. cm-1). TDS 0.15 (± 0.12 ppt). DO 7.4 (± 3.9 mg.L- 1).

Etymology:—Due to Serra da Jiboia, type locality

Notes:— Cosmarium amoenum var. jiboensis is morphologically similar to C. amoenum var. mediolaeve Nordstedt (1887:160) however this latter differs by having no granules in midregion of the semicells and elliptic cells in apical view. The newly described variety was found to be widely distributed in the bromeliads at Serra da Jiboia during all of the sampling periods, suggesting that it is well-adapted to phytotelmata conditions.

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).