Pseudostaurosira undulata Van de Vijver & Kusber, 2022

Vijver, E. Cramer Bart Van de, 2022, Typification and transfer of Fragilaria undulata C. E. Cramer to the genus Pseudostaurosira (Staurosiraceae, Bacillariophyta) with some notes on the diatom species described by Carl E. Cramer, Notulae Algarum 225, pp. 1-5 : 2-4

Pseudostaurosira undulata Van de Vijver & Kusber , nom. nov.

Replaced synonym: Fragilaria undulata C.E.Cramer in Hedwigia 11: 65, pl. XII: fig. 7. 1863, nom. illeg., non Fragilaria undulata Corda ( Corda 1835: 207, pl. IV: figs, 39, 40) nec “ Fragilaria undulata Ehrenberg ” ( Ehrenberg 1854: 108), nom. nud.

Lectotype (here designated): BR -4683, slide prepared from Rabenhorst sample 1441 (exsiccata Algen Sachens & Europa’s) in BR (Meise Botanic Garden, Belgium). The lectotype is represented here by Fig. 6. Duplicates of the Rabenhorst material No. 1441 and Wartmann & Schenk as sample 233 are found in numerous herbaria (e.g., Stafleu & Cowan 1983: 465; 1988: 93).

Registration: https://www.phycobank.org/103020

Synonyms: Fragilaria pseudoconstruens var. bigibba Marciniak ( Marciniak 1982), Staurosira robusta (Fusey) Lange-Bertalot (in Krammer & Lange-Bertalot 2000), Pseudostaurosira robusta (Fusey) D.M.Williams & Round ( Williams & Round 1987), Fragilaria construens [ var. binodis ] f. robusta Fusey (1951 , 34, pl. 1: fig. 2)

Description: Frustules rectangular in girdle view, connected to each other forming ribbon-like colonies using spatulate linking spines ( Figs 3 , 16). Valves linear, bigibbous with a clear central constriction. Apices protracted, rostrate. Valve dimensions (n=30): length 10–19 µm, width (largest width at undulations) 4–5 µm, width (at constriction) 2.5–3.0 µm. Sternum broad, linear to linear lanceolate. Central area absent. Striae uniseriate, composed of 1–3 large, rounded to transapically elongated, marginal areolae, internally closed by volae, 16–17 in 10 µm (Figs 18, 19, 20). Rimoportulae absent. Apical pore field small, composed of a few small pores at the apices (Fig. 18). Mantle plaques clearly visible at the mantle edge (Fig. 16). Girdle bands very narrow, plain (Figs 16, 21). Occasionally, deformed valves present in the population showing apical asymmetry (Figs 14, 15).

The discrepancy in valve length between the observed value (10–19 µm) and the reported length in Cramer (1863) is striking. However, analysis of the original material revealed no valves combining the morphology and the given measurement, indicating that the observed length range most likely is the correct one.

The authors wish to thank: Prof. Dr J. Neustupa and Dr O. Šída for their search for the original Corda material in Prague ( Czech Republic), and Dr David M. Williams for his valuable comments on the Cramer material and the morphology of the discussed species.

Cleve, P.T. (1894). Synopsis of the naviculoid diatoms. Part I. Kongliga Svenska Vetenskapsakademiens Handlingar Series 4 26 (2): 1–194, 5 pls.

Corda, A.J.C. (1835). Observations sur les animalcules microscopiques, qu'on trouve auprès des eaux thermales de Carlsbad. Almanach de Carlsbad 5: 166–211, pls I-VI.

Cramer, C.E. (1863). Algologische Notizien. Hedwigia 11: 61–66.

Cramer, C.E. (1869 '1868'). Ueber einige Meteorstaubfälle und über den Saharasand. Schweizerische meteorologische Beobachtungen 5: [vii]-xviii, pls I, II.

De Toni, G.B. (1892). Sylloge algarum omnium hucusque cognitarum. Vol. II. Bacillarieae; sectio II. Pseudoraphideae. Typis Seminarrii, Patavii., pp. 491–817.

Ehrenberg, C.G. (1854). Mikrogeologie. Das Erden und Felsen schaffende Wirken des unsichtbar kleinen selbstständigen Lebens auf der Erde. pp. 1–374. Leipzig: Verlag von Leopold Voss.

Fusey, P. (1951). Contribution à la flore algologique de Bretagne. Diatomées de la Région de Corlay (Côtes-du-Nord). Bulletin de Microscopie Appliquée, Paris, 2nd series 1(2): 31–50.

Krammer, K. & Lange-Bertalot, H. (2000). Bacillariophyceae, 3. Teil: Centrales, Fragilariaceae, Eunotiaceae. In: Süsswasserflora von Mitteleuropa. Band 2/3 (ed. 2). (Ettl, H., Gerloff, J. Heynig, H. & Mollenhauer, D. Eds), pp. 1–599. Heidelberg: Spektrum Akademischer Verlag.

Manguin, E. (1954). Contribution à la connaissance biologique des boues lacustres du Lac Pavin (Puy-de-Dôme). Annales de l'Ecole Nationale des Eaux et Forêts et de la Station de Recherches et Experiences 14 (1): 1–19, 3 pls, 1 table.

Marciniak, B. (1982). Late glacial and Holocene new diatoms from a glacial lake Przedni Staw in the Piec Stawów Polskich Valley, Polish Tatra Mts. Acta Geologica, Academiae Scientiarum Hungariacae 25 (1– 2): 161–171.

Rabenhorst, L. (1863). Die Algen Europa's. Decas 145–146.

Stafleu, F.A. & Cowan, R.S. (1983). Taxonomic literature IV: P-Sak (2 nd ed.). Utrecht, Antwerpen: Bohn, Scheltema & Holkema; The Hague, Boston: dr. W. Junk Publishers. 1214 pp.

Stafleu, F.A. & Cowan, R.S. (1988). Taxonomic literature VII: W-Z (2 nd ed.). Utrecht, Antwerpen: Bohn, Scheltema & Holkema; The Hague, Boston: dr. W. Junk Publishers. 653 pp.

Sypniewski, F. (1860). Okrzemki (Diatomaceae) okolic Poznania wraz, z krótka charakterystyka wszystkich rodzajów okrzemek w wodach słodkich: według analitycznej metody. Roczniki Towarzystwa przyjaciół NAUK Poznańskiego 1: 493-583, 5 pls.

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

Wartmann, F.B. & Schenk, B. (1862 –1882). Schweizerische Kryptogamen unter Mitwirkung mehrerer Botaniker. Centuries I–XI, fascicles I–XVIII, numbers 1–900. Sankt Gallen (Scheitlin & Zollikofer), Hottingen.

Wartmann, F.B. & Schenk, B. (1864). Schweizerische Kryptogamen. St. Gallen. 1863. Fasc. V, VI, VII und VIII. Nr. 201 –400. Hedwigia 4: 58–60.

Williams, D.M. & Round, F.E. (1987). Revision of the genus Fragilaria. Diatom Research 2: 267– 288, 58 figs.

Figures

Figs 1–4. Pseudostaurosira undulata Van de Vijver & Kusber, nom. nov. LM and SEM pictures taken from lectotype material (BR-4683, Rabenhorst sample 1441). Fig. 1. Original description of Fragilaria undulata in Cramer (1863: 65). Fig. 2. Original drawings of Fragilaria undulata in Cramer (1863, fig. 7). Figs 3–15. Several valves showing part of the entire cell cycle. Note the deformed valves in figs 14 & 15. Fig. 3. shows two frustules connected to each other forming a ribbon-like colony. Fig. 16. SEM view of several valves connected to each other using spatulate linking spines. Fig. 17. SEM external view of an entire valve. Fig. 18. SEM external view of two valves showing their apical pore field. Fig. 19. SEM internal view in oblique view showing the spatulate spines. Fig. 20. SEM internal view of an entire valve showing the internal volae. Fig. 21. Girdle band. Scale bars represent 10 µm.