Pegethrix indistincta Mai, Johansen et Bohunická, 2018

Mai, Truc, Johansen, Jeffrey R., Pietrasiak, Nicole, Bohunická, Markéta & Martin, Michael P., 2018, Revision of the Synechococcales (Cyanobacteria) through recognition of four families including Oculatellaceae fam. nov. and Trichocoleaceae fam. nov. and six new genera containing 14 species, Phytotaxa 365 (1), pp. 1-59 : 24-27

publication ID	https://doi.org/ 10.11646/phytotaxa.365.1.1
DOI	https://doi.org/10.5281/zenodo.13704860
persistent identifier	https://treatment.plazi.org/id/03BFDE64-6C79-FF9E-009A-F95EFEDFFC63
treatment provided by	Felipe
scientific name	Pegethrix indistincta Mai, Johansen et Bohunická
status	sp. nov.

Treatment

Pegethrix indistincta Mai, Johansen et Bohunická , sp. nov.

Diagnosis: ―Morphologically intermediate between other species, differing in the absence of spiraling and nodule formation; with conserved ITS domains almost identical in shape to D1-D1’ helix of P. convoluta ( Fig. 6d View FIGURE 6 ). Distinguishable from this species in the adenine residue opposite the basal 3’ unilateral bulge of the D1-D1’ helix and sequence from position 1–15/69–90 ( Figs. 6d View FIGURE 6 ), and the V3 helix sequence and structure ( Figs. 9d View FIGURE 9 ).

Description:— Colony bright blue green or olive-green. Filaments long, with variation in width between young and mature trichomes ( Figs. 13a View FIGURE 13 ), rarely singly or doubly false branched ( Figs. 13a–b View FIGURE 13 ), rarely with more than one trichome sharing a common sheath ( Fig. 13c View FIGURE 13 ), 2.3–4.0 μm wide. Sheath firm, usually attached to trichome, occasionally widened, rarely irregular and stratified ( Fig. 13d View FIGURE 13 ), absent in immature filaments or hormogonia. Trichomes untapered, not or slightly constricted at distinctly visible crosswalls, with necridia ( Figure 13c–d, f View FIGURE 13 ), with meristematic zones, 1.9–3.3 μm wide. Hormogonia short ( Figs. 13e–f View FIGURE 13 ). Cells typically isodiametric, often shorter than wide especially in meristematic zones ( Fig. 13f View FIGURE 13 ), slightly longer than wide in young trichomes ( Fig. 13a–b View FIGURE 13 ), (1.3)–1.7–2.7 μm long. End cells rounded.

D1-D1’ helix of the 16S–23S ITS region 91 nucleotides long having the basal 3’ side loop of 8 unpaired nucleotides (5’-CAUCCCAA-3’) opposed by a single adenine residue, with multiple internal loops at positions 14–15/69–70, 19–23/60–65, 26–27/56–57 and 32–33/50–51. Terminal loop with 4 nucleotides, with sequence 5’-GAAA-3’ ( Fig. 6d View FIGURE 6 ). Box B helix is identical to P. convoluta with 36 nucleotides, bearing 6 nucleotides at terminal loop ( Fig. 7c View FIGURE 7 ). No V2 helix present between tRNAAla and tRNAIle. V3 helix 110 nucleotides long, with one basal internal loop (5–6/101), with one unilateral bulge at position 12–14, several small internal loops at positions 23–27/88–89, 30–32/84–85, 35–36/79–81, 42–45/71–73 and 49–51/64–67. Terminal loop of 6 nucleotides, bearing sequence of 5’-GUAAUA-3’ ( Fig. 9d View FIGURE 9 ).

Etymology:— indistinctus (L.): indistinct, without morphological apomorphies that distinguish it from the other species.

Type locality: ―Lower Calf Creek Falls site, Grand Staircase-Escalante National Monument, 37°49’44.77’’ N-111 °25’12.58”W, collected on 15 August 2006 by Markéta Bohunická. Large seep wall and waterfall in Navajo Sandstone, in GSENM, Kane County, Utah, USA. Found in black compact microbial mat.

Holotype here designated:— BRY 37774 About BRY !, Herbarium for Nonvascular Cryptogams, Monte L., Bean Museum, Provo, Utah.

Isotypes here designated: ― BRY 37775! and BRY 37776!, Herbarium for Nonvascular Cryptogams, Monte L., Bean Museum, Provo, Utah.

Reference strain: ―GSE-TBC-7GA, Algal Culture Collection at John Carroll University, Cleveland, USA. Additional reference strains: GSE-TBC-7GB and GSE-TBD 1-7G, Algal Culture Collection at John Carroll University, Cleveland, USA.