Sirodotia kennedyi A.L.Szinte, J.C.Taylor & M.L.Vis

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

Sirodotia kennedyi A.L.Szinte, J.C.Taylor & M.L.Vis

( Fig. 6 G-I)

Phycologia 194 (2020).

S. masoalensis E. Fischer, D. Killmann & D. Quandt, Plant and Fungal Systematics 65: 164 ( Fischer et al. 2020).

TYPE. — Coll. M. P. Kennedy, 07.VII.2011 (holo-, SANDC [ SANDC 19-566]; iso-, BHO [ BHO A-0946]).

TYPE LOCALITY. — Zambia, Mutinondo River, Mutinondo Wilderness, 12°16.101’S, 31°22.869’E.

DISTRIBUTION. — Africa: Zambia and Madagascar.

REPRESENTATIVE DNA SEQUENCES. — COI-5P ( MT109276 ), rbc L ( MN974518 , MT109266 ).

Description

Plants dioecious; whorls 115-315 µm in diameter; primary fascicles, 3-5 cells; proximal cells cylindrical or ellipsoidal; distal cells obovoidal or ellipsoidal; secondary fascicles present, covering half to the entire internode; spermatangia spherical, on primary or secondary fascicles, 6-8 µm in diameter; carpogonial branches composed of 3-4 disc- or barrel shaped cells, arising from proximal cells of primary fascicles, short, 16-22 µm in length; carpogonia with sessile, elongate pear-shaped, elongate conical or irregularly shaped trichogynes, 25-40 µm in length, 7-11 µm in diameter; gonimoblast filaments with erect branches of one cell; carposporangia obovoidal or ellipsoidal, 9-10 µm in length, 5-7 µm in diameter.

Remarks

This species was recently described by Szinte et al. (2020) and it is most closely comparable to S. huillensis based on the reduced whorls (162-364 µm in diameter), shorter carposporangia (8-10 µm in length, respectively) and the occurrence in Africa. Sirodotia kennedyi differs from S. huillensis in number of primary fascicle cells, 3-5 versus 5-9(-10), respectively. In addition, they are genetically divergent. The recently described species S. masoalensis did not differ from S. kennedyi in morphology and DNA sequence and is here proposed as a synonym.

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).