The taxonomic recognition of Pterothamnion crispum (Rhodophyta, Ceramiales), with a survey of the carposporophyte position in genera of the Antithamnieae
Athanasiadis, A. (1985). The taxonomic recognition of Pterothamnion crispum (Rhodophyta, Ceramiales), with a survey of the carposporophyte position in genera of the Antithamnieae. Br. Phycol. J. 20(4): 381-389. http://dx.doi.org/10.1080/00071618500650391
In: British Phycological Journal. British Phycological Society: London. ISSN 0007-1617; e-ISSN 2331-2238, more
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| Abstract |
The marine alga commonly referred to as Antithamnion plumula (Ell.) Thur. var. crispum (Ducl.) Hauck was cultured from the North Aegean Sea and the Channel Islands. The two strains interbred successfully, demonstrating a Polysiphonia-type life history. Chromosome counts in gametophytes and tetrasporophytes gave 24±2 and 48±4, respectively. Crossing attempts with Pterothamnion plumula (Ell.) Näg. from the Swedish west coast, with the same approximate numbers of chromosomes, were unsuccessful. On the basis of the crossing results a specific status for this alga is recognized and features of its reproductive morphology are examined.A lateral position of carposporophytes is described for the first time in that species and it is found to occur similarly in P. plumula. Number of procarps (1–6), late or early initiation and their fertilization, and continuation or suppression of fertile axes during carposporophyte development are found to be variable features, and consequently unreliable taxonomic criteria at the level of species. The relationship of the genera Antihamnion, Pterothamnion and Platythamnion is studied, and resurrection of the name Pterothamnion crispum (Ducl.) Näg. is recommended.A survey of the position of the carposporophyte within six genera of the Antithamnieae, Antithamnion, Antithamnionella, Balliella, Pterothamnion, Platythamnion, and Scagelia, shows that three types occur: apical, lateral and intercalary. |
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