The fourth part of a revision of linear-leaved species of the genus Potamogeton in the Czech Republic is given, dealing with P. pusillus s.l. and P. trichoides. The appropriate taxonomic concept and species delimitation within P. pusillus s.l. are discussed. Because of still unresolved taxonomic difficulties and high percentage of specimens that cannot be assigned to one of the two traditionally distinguished species, P. pusillus s. str. (syn. P. panormitanus) and P. berchtoldii, the broader concept of P. pusillus s.l. has tentatively been adopted in this revision. This species complex is widespread in the Czech Republic, absent only in relatively small areas of the highest elevations and the driest areas without suitable biotopes. P. pusillus s.l. is the commonest taxon of Potamogeton in standing waters. P. trichoides, a well defined species distinguished by several morphological characters, occurs scattered mainly in S, C and E Bohemia and S and C Moravia, with most localities concentrated in S Bohemia. It is considered as strongly threatened species of the Czech flora. Species descriptions, relevant synonyms, illustrations, a list of specimens examined and distribution maps are provided for both species. P. rutilus was once reported from the Czech Republic in error. No specimen from this country has been found in herbaria.
The last part of a revision of linear-leaved species of the genus Potamogeton in the Czech Republic focuses on P. pectinatus. This species is the only member of subgenus Coleogeton occurring in this country. Species description, relevant synonyms, illustrations, a list of specimens examined and a distribution map are provided. P. pectinatus is widespread in the Czech Republic; it is the most common Potamogeton species particularly in runningwaters. P. pectinatus still quite often grows in most lowland rivers and their basins.
A new genus, Vindobonella gen. n. (Acerentomidae s. l.), and a new species, Vindobonella leopoldina sp. n., are described from Vienna. The new genus belongs to a group characterized by a reduced labial palp and a non-modified striate band on abdominal segment VIII.
A review of West Palaearctic species of the genus Eloeophila Rondani, 1856 is presented. Three species are redescribed, viz. E. czernyi (Strobl in Czerny & Strobl, 1909), E. laciniata (Edwards, 1928), and E. pusilla (Kuntze, 1920). A lectotype of the latter is designated. Eloeophila albofascia (Alexander, 1975) is established as a new junior synonym of E. apicata (Loew, 1871). Descriptions are provided of E. bipartita sp. n. (North Italy), E. delmastroi sp. n. (North Italy), E. lucasi sp. n. (South Italy and Sicily), E. maroccana sp. n. (Morocco, Spain), E. martinovskyi sp. n. (South Italy), E. minor sp. n. (Czech Republic, Slovakia), E. pectinistylus sp. n. (Spain), E. punctulata sp. n. [Cyprus, Greece (Crete)], E. sparsipunctum sp. n. (Bulgaria), and E. tigricosta sp. n. (Spain). A key to males of all West Palaearctic species is presented.
Minuaria kabylica (Pomel) Dvořáková, a species of the section Polymechana Mattf., is defined in terms of taxonomy and chorology. The taxa Minuartia verna subsp. kabylica (Pomel) Maire et Weiller (= Alsine kabylica Pomel) from Northern Africa, and M. grandiflora (C. Presl) Dvořáková from Sicily are taxonomically identical. The distribution of M. kabylica is limited to the Atlas mountain system in Northern Africa and to the mountains of northern Sicily. The seed coat of M. kabylica is documented by an SEM photograph.