The genus Jaagichlorella Reisigl (Trebouxiophyceae, Chlorophyta) and its close relatives: an evolutionary puzzle Author Darienko, Tatyana University of Göttingen, Albrecht-von-Haller-Institute of Plant Sciences, Experimental Phycology and Sammlung für Algenkulturen, D- 37073 Göttingen, Germany & M. G. Kholodny Institute of Botany, National Academy Science of Ukraine, Kyiv 01601, Ukraine Author Pröschold, Thomas University of Innsbruck, Research Department for Limnology, A- 5310 Mondsee, Austria text Phytotaxa 2019 2019-01-14 388 1 47 68 http://dx.doi.org/10.11646/phytotaxa.388.1.2 journal article 10.11646/phytotaxa.388.1.2 1179-3163 13725500 Jaagichlorella africana Darienko & Pröschold sp. nov. ( Fig. 4J–T ) Description: Young cells are spherical (5.5–6.4 μm in diameter) or slightly ovoid to irregular (6.4 x 5.5 μm in size). Cell wall by young cells is relative thick. Chloroplast cup-shaped to saucer-shaped, covers 2/3 of the cell with a single, distinct pyrenoid surrounded by several starch grains. Mature vegetative cells are mostly spherical, 7.3–9.1 μm, sometimes 11.8 μm in size. Cell wall is relative thick. Chloroplast deep cup-shaped, often with small incisions or wavy margins, in the bottom part sometimes slightly removed from the cell wall. Chloroplast thick, with dark-green color, which covers 2/3 or more of the cell. The single pyrenoid is distinct surrounded by many starch grains. Numerous, small vacuoles and inclusions are present. Old cells often have a reduced chloroplast, which is only slightly removed from the cell wall. Reproduction is by 2-4-8 unequal autospores. Autospores have a saucer-shaped or band-shaped chloroplast with a visible pyrenoid. Liberation of spores by rupture of the sporangial cell wall. Remains of the sporangial cell wall are usually bag-shaped. Often one autospore remains in the cell wall and develops to a mature cell or a new sporangium. Autosporangia are spherical or often irregular, 9.1–11.8 μm, sometimes up to 15.5 μm in size. Large autospores between 6.4–11.8 μm, small autospores 3.7–5.4 μm in size. SSU and ITS rDNA sequences (GenBank: MH780938) and ITS-2 Barcode BC- 2 in Fig. 3 . Type locality: Lithophytic on the surface of a concrete wall, Namibia . Holotype (designated here): The authentic strain SAG 2213 is cryopreserved in a metabolic inactive state at the Culture Collection of Algae ( SAG ), University of Göttingen , Germany . Iconotype (designated here to support the holotype ): Fig. 4J in this study. Etymology : The species epithet indicates the origin of this species.