Gomphonema graciloides, Hustedt, 1965

Guerrero División Ficología, José M., 2025, Lectotypification of Gomphonema correntinum Frenguelli (Gomphonemataceae, Bacillariophyceae), Notulae Algarum 369, pp. 1-4 : 2-4

Gomphonema graciloides was described from mosses at 1000 m in Parque Nacional do Itatiaia, Brazil ( Hustedt 1965: 410, figs 43, 44), is the most similar species and could be easily confused with G. correntinum . However, it is distinguished by its slender valves, less asymmetrical to the apical axis, and its much lower areola density (28 in 10 μm).

We found that smaller specimens of G. perapicatum , a species described from Guyana, are similar in outline to G. correntinum while the larger ones are clearly different. Moreover, the former has larger valves (40–75 x 12–13.5 μm), lower stria (7–8 in 10 μm) and areola (15–18 in 10 μm) densities, and areolae clearly discernible under LM ( Metzeltin & Lange-Bertalot 2007).

We are grateful to Michael D. Guiry and an anonymous reviewer for comments and suggestions that improved our manuscript.

Frenguelli, J. (1933). Contribuciones al conocimiento de las diatomeas Argentinas. VII. Diatomeas de la región de los Esteros del Yberá (en la Provincia de Corrientes). Anales del Museo Nacional de Historia Natural 37: 365475.

Frenguelli, J. (1953). XIX Contribución al conocimiento de las diatomeas argentinas. Diatomeas del Territorio Nacional de Misiones. Revista del Museo de la Ciudad Eva Perón Nueva Serie 8 (Botánica No. 32): 63–86, 3 pls.

Guiry, M.D. & Guiry, G.M. 2025. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 01 April 2025.

Herbst, N. & Maidana, N.I. (1989). Diatoms of Chaco (República Argentina): 1. Nova Hedwigia 49 (1/ 2): 207–232, incl. I pl., 1 fig. [map].

Hustedt, F. (1965). Neue und wenig bekannte diatomeen. IX. Süsswasserdiatomeen aus Brasilien, insbesondere des Amazonasgebietes. Internationale Revue der gesamten Hydrobiologie 50 (3): 391–410.

Metzeltin, D. & Lange-Bertalot, H. (2007). Tropical diatoms of South America II. Special remarks on biogeography disjunction. Iconographia Diatomologica 18: 1–877, incl. 296 pl.

Radhakrishnan, C., Das, S.K., Kumar, V., Kociolek, J.P. & Karthick, B. (2020). A new freshwater Gomphonema Ehrenberg (Bacillariophyta) species from Eastern Himalayas, India. Fottea 20 (2): 128–136, 35 fig., 1 table.

Turland, N.J., Wiersema, J.H., Barrie, F.R., Greuter, W., Hawksworth, D.L., Herendeen, P.S., Knapp, S., Kusber, W.-H., Li, D.-Z., Marhold, K., May, T.W., McNeill, J., Monro, A.M., Prado, J., Price, M.J. & Smith, G.F., editors (2018). International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress

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Shenzhen , China, July 2017. Regnum Vegetabile, Vol. 159. pp. [i]-xxxviii, 1–253. Glashütten: Koeltz Botanical Books .

Vouilloud, A.A., Guerrero, J.M., & Morales, E.A. (2022). Fragilaria pinnata var. subcapitata Frenguelli , typification and current taxonomic status. Phytotaxa 566(1), 133–139.

No. 369 (10 April 2025)

ISSN 2009-8987