engleski

Analysis of the type material of Achnanthes hauckiana Grunow (Achnanthaceae, Bacillariophyceae)

The type material of Achnanthes hauckiana Grunow has been investigated using light and scanning electron microscopy. The species, transferred to the genus Planothidium, was frequently reported from brackish and even marine environments. The original Grunow material was collected from a karstic spring near Trieste. Analysis of the material and of samples collected from the Croatian Krka River, resulted in a better understanding of the morphology of Planothidium hauckianum and a better characterization of the diatom flora of which it is a dominant component. The paper compares the species with similar Planothidium species from the P. delicatulum complex and revises published images of P. hauckianum in literature, making it clear that all reported and illustrated brackish populations of P. hauckianum belong to different, often unknown species. The presence of Planothidium hauckianum is limited to karstic spring areas, most likely showing a very restricted biogeographical distribution.

Planothidium ; ecology ; type material ; Croatia ; morphology

Environmental Research & Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), Belvaux, Luxembourg ; Research Department, Meise Botanic Garden, Meise, Belgium ; Department of Biology – ECOBE, University of Antwerp, Wilrijk, Belgium