Sirodotia suecica Kylin

Rossignolo, Natalia L., Vis, Morgan L., Paiano, Monica O., Eloranta, Pertti, West, John A., Ganesan, E. K., Yasmin, Farishta, Lim, Phaik-Eem & Necchi, Orlando Jr, 2021, Revision of the genus Sirodotia Kylin (Batrachospermales, Rhodophyta) with description of four new species, Cryptogamie, Algologie 20 (8), pp. 93-127 : 108-110

Sirodotia suecica Kylin

( Fig. 6 J-N)

Nova Acta Regiae Societatis Scientiarum Upsaliensis, ser IV, 3: 38 ( Kylin 1912). — Batrachospermum suecicum (Kylin) Necchi & Entwisle, Phycologia 29: 486 (1990).

Sirodotia fennica Skuja, Archiv für Protistenkunda 74: 297 (1931). Sirodotia sinica C. C. Jao, Sinensia 12: 267-270 (1941).

Sirodotia tenuissima (Collins) Skuja ex Flint , American Journal of Botany 35: 431 (1948).

Sirodotia acuminata Skuja ex Flint , American Journal of Botany 37:755 (1951).

Sirodotia segawae Kumano , Botanical Magazine, Tokyo 95: 128-131 (1982).

Sirodotia yutakae Kumano , Botanical Magazine, Tokyo 95: 126- 129 (1982).

Sirodotia goebelii Entwisle & Foard , Australian Systematic Botany 12 (4): 610 (1999).

TYPE. — H. Kylin, 3.VIII.1909 (lecto-, LD; isolecto-, UPS [ UPS A-653877]).

TYPE LOCALITY. — Sweden, Skäne, Osby; 56°23’01”N, 13°59’34”E.

ADDITIONAL SPECIMEN EXAMINED. — BHO A-0264, SJRP 32581, SJRP 32582, SJRP 32583, NSW 799516, MEL 2033246 A, 2268154 A, WELT A 027220 ( Appendix 1).

DISTRIBUTION. — Africa, Asia, Australasia, Europe and North America.

R EPRESENTATIVE DNA SEQUENCES. — COI-5P ( MW053472 , MW053473 , MW053474 ), rbc L ( MW053484 , JF344724 , JF344725 ) and LSU ( MW053504 , MW053505 ).

Revised description

Plants monoecious or dioecious; whorls (85-)135-850 µm in diameter; primary fascicles, 4-12(-13) cells; proximal cells cylindrical, obovoidal, ellipsoidal, fusiform or ovoidal; distal cells ellipsoidal, obovoidal or subspherical; secondary fascicles abundant, covering the entire internode; spermatangia spherical or ellipsoidal, 1-3, few or abundant on primary or secondary fascicles, (4-)5-9 µm in diameter; carpogonial branches composed of (1-)2-9 disc- or barrel shaped cells, short, 5-40 µm long, arising from periaxial, proximal or median cells of primary fascicles and cortical filaments, rarely on secondary fascicles; carpogonia with sessile, elongate cylindrical, ellipsoidal, elongate pear-shaped or irregularly shaped trichogynes, (15-)19-48 µm in length, (4-)5-16 µm in diameter; gonimoblast initial developing from the nonprotuberant side of the carpogonium; gonimoblast filaments with erect branches of 2-9 cells; carposporangia obovoidal, ellipsoidal, spherical or pear-shaped, 10-21 µm in length, 6-11 µm in diameter.

Remarks

This species has a broad geographic distribution and a broad range for the morphological features. It is comparable to the other species with large carposporangia and spermatangia 1-3 on primary fascicles (e.g. S. delicatula , S. delicatuliformis Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov., S. amazonica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov., S. cryptica Necchi, N.L.Rossignolo & M.O.Paiano , sp. nov. and S. aquiloamericana ). The species is clearly differentiated by the unique character of gonimoblast initial developing from the non-protuberant side of the carpogonium.Molecular data also showed the species to be clearly distinct from all others in the genus (rbc L, COI-5P and LSU). The heterotypic synonyms considered in this study were based on the analysis of types, protologues and when possible, molecular data. The morphological characters used to distinguish these species ( S. fennica , S. sinica , S. tenuissima , S. acuminata , S. segawae , S. yutakae and S. goebelii ) overlap most characters (breeding system, internode length, carpogonial branch growth and length and carpogonia length) of S. suecica and they are not useful due to the variation observed across this species. Molecular data for S. tenuissima and S. goebelii showed these taxa to have very similar rbc L sequences to S. suecica ( Lam et al. 2012) . Based on the analysis of type specimens and protologues of S. segawae and S. yutakae , we did not confirm the existence of specialized spermatangial branches on primary fascicles and secondary fascicles ( S. yutakae ) or on specialized filaments on cortical filaments or on shortened involucral filaments of carpogonial branches ( S. segawae ). We conclude that S. segawae , S. yutakae and S. sinica should be placed in synonymy with S. suecica . Overall, we accept only one taxon including these other names as synonyms, that is characterized by the gonimoblast initial developing from the opposite side of the basal protuberance of carpogonium.

Figures

FIG. 6. — Morphological features of Sirodotia species: A-E. Sirodotia huillensis (Welwitsch ex West & G.S.West) Skuja (photos taken from sample BHO A-1447): A, obconical whorls; B, C, primary fascicles with spermatangia (arrows); D, E, carpogonia with irregular trichogyne (arrowheads) showing the basal hemispherical protuberance (double arrows) and gonimoblast initial developing from the protuberant side of the carpogonium (arrow); F, carposporangia (arrows) and erect gonimoblast filaments (arrowheads). G-I, Sirodotia kennedyi (photos taken from sample BHO A-0946): G, obconical whorls; H, primary fascicles (arrows) and carpogonium with irregular trichogyne (arowhead) and basal hemispherical protuberance (double arrowhead); I, carposporangia (arrow), prostrate (arrowhead) and erect (double arrowhead) gonimoblast filaments. J-N, Sirodotia suecica Kylin (photos taken from samples BHO A-0266, SJRP32582, SJRP32583): J, obconical whorls; K, primary fascicles with terminal spermatangia (arrows); L, carpogonia with mature trichogyne (arrows) and basal hemispherical protuberance (arrowhead); M, fertilized carpogonium with attached spermatium (arrow) and gonimoblast initial (double arrowhead) on the opposite side of the basal protuberance (arrowhead); N, carposporangia (arrows), prostrate (arrowhead) and erect (double arrowhead) gonimoblast filaments. Scale bars: A, G, J, 100 μm; B-C, H-I; D-F, L-M, 10 μm; K, 50 µm. B-F, redrawn from Skuja (1931); H-I, modified from Szinte et al. (2020); M, redrawn from Necchi et al. (1993).