The diversity of Lycoperdaceae in Israel was studied. Molecular phylogenetic relationships within the family, and genus Lycoperdon in particular, were inferred using original ITS rDNA sequences of 58 samples belonging to 25 species from Israel and six other countries, together with 66 sequences stored in the GenBank database. The current molecular phylogenetic study recovered the family Lycoperdaceae as a monophyletic group, which was supported in both maximum likelihood and Bayesian analyses. The clades corresponding to the genera Apioperdon, Bovista, Calvatia, Disciseda, and Lycoperdon were revealed. The taxonomic structure of the named genera was partially resolved. Within the genus Lycoperdon, some species received significant statistical support; however, their relationships, as well as the problem of the genus monophyly, mostly remained questionable. As a result of a thorough literature survey, extensive sample collection, and studies of the material stored in the Herbarium of the Institute of Evolution, University of Haifa (HAI, Israel), fifteen species representing five genera were found in the territory of Israel. Six species, namely Apioperdon pyriforme, Bovista aestivalis, Calvatia candida, Lycoperdon decipiens, L. niveum, and L. perlatum, are new additions to the diversity of Lycoperdaceae in Israel. Detailed macro- and micromorphological descriptions, ecology, geography, and critical notes, together with light microscopy photos and SEM micrographs, are provided. In-depth discussion on some taxonomically challenging species is presented.

Sclerogaster compactus, Wakefieldia macrospora, and Setchelliogaster tenuipes are reported from Israel for the first time. All of them are new for the Middle East. Detailed macro- and micromorphological descriptions, ecology, geography, and critical notes along with pictures of light and scanning electron microscopy are given.

A new species of Dinoflagellata—Protoperidinium euxinum Krachmalny sp. nov. (Protoperidiniaceae, Peridiniales) was described from the plankton of Odessa Bay (Black Sea). The species is morphologically close to P. steinii, P. mediterraneum and P. joergensenii. It differs from the listed species in elongated pentagonal body shape, conical epitheca with straight or concave lateral sides, inverse trapeziform hypotheca, and asymmetrical, laterally compressed plate 2a. Dimensions: 73.3–99.0 µm in length and 38.8–51.6 µm in width. Pictures and photomicrographs of the novel species are presented, along with detailed description and discussion.

To date, 59 species (61 including infraspecific taxa) of the heterotrophic genus Protoperidinium have been found in the Black Sea. With rare exceptions, the records of most species were not confirmed by either line drawings or microphotographs, and lacked indications of important diagnostic traits. To partially correct these deficiencies, we conducted morphological examinations of the dominant Protoperidinium species in the Black Sea. The study provides original descriptions, line drawings, and microphotographs of 22 species of Protoperidinium with their global distribution maps. Protoperidinium quadrioblongum is reported from the Black Sea for the first time.

A new heterotrophic dinoflagellate, Protoperidinium vietnamicum sp. nov. is described from the coastal waters of Vietnam. It is characterized by an elongated, pentagonal to pyriform body in ventral and dorsal view, with moderate dorsoventral compression. Epitheca is tapering into a robust apical horn, which is shorter than the antapical horns. Cingulum is equatorial, descending by about 0.50–0.75 of its width. Sulcus is wide, shallow, and slightly oblique. Plate 1′ is ortho‐type, and intercalary 2a and 3a plates are pentagonal. Plate 1a is quadrangular, having approximately one third the area of plate 3a. Additionally, the new combination Protoperidinium curvicorne (Böhm) comb. nov. is proposed. It is a large cell‐sized species with a round, broad body, and strong dorsoventral compression. Its epitheca narrows abruptly into a slender apical horn strongly tilted towards the ventral side. The cingulum is narrow, shallow, descending by about 1.5–2.0 cingular widths, and strongly inclined relative to the equatorial plane of the cell. The plate 1′ is ortho‐type, and 2a and 3a are pentagonal. Specimens from the type locality of the taxon were examined. Both species are provided with detailed descriptions and are illustrated with line drawings, as well as with light microscopy images and SEM micrographs. An in‐depth discussion and comparison with similar species are presented.