Contribution
de
Lange-Bertalot, H.
Nova Hedwigia Band 60 Heft 1-2 (1995), p. 241 - 252
7 références bibliographiques
publié: Mar 7, 1995
DOI: 10.1127/nova.hedwigia/60/1995/241
ArtNo. ESP050006001021, Prix: 29.00 €
Abstract
A new genus is described in the family Rhoicospheniaceae, with two subgenera: Gomphosphenia and Rhoicosphenula. Type species of the new genus and nominate subgenus Gomphosphenia is G. lingulatiformis. It is transferred although it was just recently described as a new species in Gomphonema. The reason is that a distinct cluster of some few species with wedge-shaped frustules and valves does no longer fit in the new restricted concept of the genus Gomphonema but without doubt in the emended concept of Rhoicospheniaceae sensu Medlin & Round 1986. The second subgenus is based on Gomphosphenia paradoxa, a new species of neotropical origin. The combination of single characters is unique although most of them can be found — in different combination — in other genera of the emended family Rhoicospheniaceae but not in the Gomphonemataceae (sensu Round et al. 1990). Moreover, the autecology of all the taxa of both new subgenera, i. e. their habitats in acidic or moderately alkaline freshwater distinguishes them from all taxa of Cuneolus, Gomphonemopsis, Gomphoseptatum, Campylopyxis living in marine or brackish sites.
Mots-clefs
cluster • species • neotropical origin • frustule • valve