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Morphology, anatomy and reproduction of the eastern Mediterranean coralline Tenarea tortuosa and its relationship to members of the Lithophylloideae and Mastophoroideae (Rhodophyta, Corallinales)
Author(s) -
Athanasiadis A.
Publication year - 1995
Publication title -
nordic journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.333
H-Index - 33
eISSN - 1756-1051
pISSN - 0107-055X
DOI - 10.1111/j.1756-1051.1995.tb02136.x
Subject(s) - biology , sexual reproduction , frond , dominance (genetics) , botany , gametophyte , mediterranean climate , ecology , zoology , pollen , biochemistry , gene
One of the most characteristic organisms of the Mediterranean flora, the endemic coralline Tenarea tortuosa , has been collected along the Cretan coast and its vegetative and reproductive structures are reassessed. Gametophytes are described for the first time and are rare, observed only in one locality on the south coast. Reproductive structures suggest that the sexual life history is triphasic, but the present collections indicate unequal representation of males, carposporophytes and tetrasporophytes, and a dominance of bisporophytes suggesting that the alga is reproducing mainly asexually. The frond of Tenarea is formed by the coordinated growth of two elements (branches), growing back‐to‐back, each showing a simple Titanodema‐type of organization; i.e. a monostromatic hypothallium of sinuous cells and a single layer of obliquely borne epithallial cells. Contiguous cells of the two opposite branches are not connected by secondary pit‐plugs, and easily glide apart if decalcified. Natural splitting of the lamellae into its two branches may also occur, and single branches may fold regenerating the back‐to‐back organization. Analogous back‐to‐back growths occur in species of the distantly related genera Goniolithon (Lithophylloideae) and Leptophytum (Melobe‐sioideae) and apparently represent cases of convergence. The affinities of Tenarea to related genera are discussed.