Conxi Rodríguez-Prieto, Alba Vergés, Noemí Sánchez, Lluís Polo, Marc Verlaque
The morphology and reproductive structures of Mediterranean species of the genus Nemastoma J. Agardh, nom. cons. (Nemastomataceae, Nemastomatales): Nemastoma dichotomum and N. dumontioides
We investigated a collection of Nemastoma J. Agardh, nom. cons. (Nemastomatales, Rhodophyta), including the Mediterranean type material of species described by J. Agardh, Kützing and Ercegovic, and recent specimens from the Mediterranean Sea, Adriatic Sea and northeastern Atlantic Ocean. Based on their habit and vegetative and reproductive structures, we confirm that: (i) all the Mediterranean specimens studied belong to the genus Nemastoma; (ii) two species of Nemastoma co-exist in the Mediterranean Sea: (a) N. dichotomum, which is characterized by great plasticity of habit, a cartilaginous thallus in its basal and middle parts, and presumed reproduction exclusively by apomixis; and (b) N. dumontioides, which is characterized by a regularly pseudodichotomous, saccate-membranous thallus, and which reproduces both sexually and probably apomictically; and (iii) the Atlantic specimens attributed to N. dichotomum belong to other genera, and so, N. dichotomum is probably endemic to the Mediterranean Sea. Thus, three species described by Kützing have been reduced to varieties of Nemastoma dichotomum: (a) var. biasolettianum (Kützing) Rodríguez-Prieto, Verlaque et Vérges comb. nov. et stat. nov., with ligulate upper parts, (b) var. caulescens (Kützing) Rodríguez-Prieto, Verlaque et Vérges comb. nov. et stat. nov., with wedge-shaped upper parts, and (c) var. incrassatum (Kützing) Rodríguez-Prieto, Verlaque et Vérges comb. nov. et stat. nov., with spathulate upper parts. Finally, Nemastoma constrictum and N. constrictum var. longitrichogynum are placed in synonymy with N. dichotomum var. caulescens.
Botanica Marina, Walter de Gruyter
Print ISSN: 0006-8055
Volume: 47, 02/2004
Pages: 38 - 52
Show full article (external site)
Show all available items of this journal
Search
