Cosmarium oliveirae 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 : 63-65

Cosmarium oliveirae G.J.P.Ramos, C.E.M.Bicudo & C.W.N.Moura sp. nov. ( Figs. 34–38 )

Cells 1.2–1.6 times longer than wide, elliptical contour, deep median constriction, closed linear sinus, dilated proximally closed; semicells subtrapeziform, basal margins retuse, subquadratic angles, lateral margins concave, rounded angles, subtruncated apex; cell wall decorated with small conical granules in rows, near the margin; semicells oblong in apical view, subelliptic in lateral view; 2-furcated chloroplast; pyrenoid 2 per semicell; cells 42–46,5 μm length, 35–28 μm width, 10–17 μm isthmus.

Holotype: material numbered ( HUEFS 224668 !) deposited at Herbário da Universidade Estadual de Feira de Santana , population partially illustrated here in LM ( Figs 34–37 ) and SEM ( Fig. 38 ).

Paratypes (here designated): HUEFS 224682, HUEFS 224707, HUEFS 224723 (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’ 7.5” S, 39°28’ 35.7” W. Sample collected by G. J. P.Ramos, C. W. N. Moura and M. A. Santos ( HUEFS 224668) on 14 January 2015. Cosmarium oliveirae occurred in samples collected in bromeliad tanks ( Alcantarea nahoumii ); T 27.8 (± 2.5 ºC). pH 6.2 (± 0.48). C 0.28 (± 0.15 mS. cm-1). TDS 0.14 (± 0.07 ppt). DO 7.2 (± 3.1 mg.L- 1).

Etymology:—the new name of the present species is given in honor of Brazilian desmidiologist Dr. Ivania Batista de Oliveira for her contribution to knowledge of desmids in Bahia.

Notes:— The newly described species is morphological similar to Cosmarium obtusatum (Schmidle) Schmidle (1898: 38) , however this latter differ by having margins faintly crenate (flattened verrucae) and elliptical semicells in apical view. Due this similarity, this taxon was identified previously for this area as C. obtusatum ( Ramos et al. 2011) . Now, after a detailed reanalysis of this taxon, especially in SEM, the ornamentation of the granules is clearly different from pattern of C. obtusatum .

Figures

FIGURES 26–48. Cosmarium majae: LM (26–33); SEM (33), ventral view (27, 29–31, 33), apical view (26), lateral view (28) and zygospore (32); C. oliveirae: LM (34–37); SEM (38), ventral view (34–35, 38), apical view (36), lateral view (37); C. pachydermum var. aethiopicum: LM (39–42); SEM (43), ventral view (39–40, 43), lateral view (41), apical view (42); C. pseudoconnatum: LM (44–47); SEM (48), ventral view (44–45, 48), apical view (46–47). Scale bar 10 μm (26–32, 34–38, 44–47), 5 μm (33), 20 μm (39–43).