Pseudochlorella J. W. G. Lund.

Pseudochlorella, originally described as Chlorellopsis by Zeitler (1954), is characterized by a coccoid type of thallus with ellipsoid to globular cells surrounded by a thin and smooth cell wall (Fig. 11). The cells may form groups and can be enclosed in mucilage. They contain a grooved or plate-like chloroplast with a spherical pyrenoid (Ettl & Gärtner 2013).

Pseudochlorella is very difficult to distinguish from Elliptochloris since they share many morphological features, including the formation of S-type and E-type autospores. However, the two genera belong to distantly related clades, the Prasiolales and the Elliptochloris -clade (Darienko et al. 2016). Some Pseudochlorella species are found in extreme environments. For example, a strain closely related to P. pringsheimii has been isolated from an extremely acidic environment of a mine in Japan (Hirooka et al. 2014). There are three accepted species names within the genus (Guiry & Guiry 2022). Two of them (the type species P. pyrenoidosa and P. signiensis) were isolated from Lecidea and Trapelia lichens, respectively (Zeitler 1954; Darienko et al. 2016).