Stigonema fremyi, Sant’Anna, Célia L., Kaštovský, Jan, Hentschke, Guilherme S. & Komárek, Jiŕí, 2013

Sant’Anna, Célia L., Kaštovský, Jan, Hentschke, Guilherme S. & Komárek, Jiŕí, 2013, Phenotypic studies on terrestrial stigonematacean Cyanobacteria from the Atlantic Rainforest, São Paulo State, Brazil, Phytotaxa 89 (1), pp. 1-23 : 8

Stigonema fremyi Sant’Anna, Kaštovský, Hentschke& Komárek, sp. nov. ( Fig. 6 )

Strata subaerophytica , fasciculata vel aggregata, tomentosa, atro-olivacea. Fila ramique similares, multiseriata, 18–50 µm lata; rami de filis principalis plus minusve ad angulum 90 o divaricati, ad apices gradatim attenuati, cum segmentis curtis terminalibus uniseriatis, ad 25 µm latis, apice rotundati. Vaginae firmae, distinctae, paucim laminosae, luteo-fuscae. Cellulae irregulariter sphaericae, 11–20 µm diametro. Heterocytae solitariae, intercalares, dimensionibus similaris cellulis vegatativis. Hormogonia curta, praecipue uniseriata, terminaliter separantur.—Habitatio: Aerophytice ad saxa et rupes facultative madidas, in montibus " Mata Atlantica " dictis, prope Campos de Jordão, provincia São Paulo, Brasilia.

Type:— BRAZIL. São Paulo: Campos do Jordão , preserved sample collected on 9 November 2002, C.L. Sant’Anna, M. T. P. Azevedo and J. Komárek (Holotype SP 427508!) .

Filaments forming dense clusters, morphologically similar to the branches which separate them from the main filaments in right angles; both polyseriate, (18)28–45(50) µm wide. Branches narrowed at the base and toward the ends, with short uniseriate segments in terminal parts, ends rounded, up to 25 µm. Sheaths firm, limited, mostly yellow-brown. Cells irregulary sphaerical, 11–20 µm diameter. Heterocytes numerous, intercalar or lateral, with the same dimensions as the cells.

Habitat:— On rocky walls.

Etymology:— Species is named to the honor of the famous French specialist in Cyanophyceae (Cyanobacteria) Abbé Pierre Frémy, who first described and documented similar Stigonema populations from African tropical localities.

Notes:— The Brazilian population with polyseriate filaments and more or less morphologically identical branches (only slightly narrower) corresponds well to the concept of S. minutum sensu Frémy (1930) . However, these specimens clearly differ from the original description of S. minutum ( Geitler 1932) by the morphology of polyseriate filaments, dimensions, ecology, and also by the occurrence in tropical habitats. The type of branching is very characteristic in the studied material as well as in Frémy´s material from Africa: branches are often characteristically narrowed at the initial point from the main filaments. Based on our studies of populations corresponding to the original description of S. minutum , we could confirm that our material, and also that of S. minutum sensu Frémy are specifically tropical species, clearly different from the typical S. minutum described in temperate regions. Thus, we named the new species S. fremyi , which includes the material from Africa identified by Frémy (1930) as S. minutum and the Brazilian material.

Figures

FIGURE 6 A–E: Stigonema fremyi. A, B: General aspects of thallus. C–E: Details of attenuated branches. Scales: 10 µm in A, B, C (use for C–E).