Phycopeltis Millardet .

Members of this epiphytic genus typically develop orange circular or irregular discs on the upper leaf surface of vascular plants (Fig. 20). The discs, often varying in shape, are formed by a single layer of laterally appressed dichotomous filaments. Chloroplasts are parietal and lack pyrenoids (Ettl & Gärtner 2013; Škaloud et al. 2018). This genus’ cell wall contains sporopollenin, a chemically inert biological polymer, and it appears to play a role in plant defences against desiccation and fungal parasites (Good & Chapman 1978). The life cycle is isomorphic (Ettl & Gärtner 2013; Škaloud et al. 2018).

Phycopeltis is non-monophyletic (Zhu et al. 2017) and currently includes 25 accepted species (Guiry & Guiry 2022). Its phylogenetic position remains poorly understood (Sanders & Masumoto 2021). Although the genus is widely distributed in tropical forests (Zhu et al. 2018), certain records indicate that it also occurs in oceanic Europe (Rindi et al. 2004). Phycopeltis sp. was isolated from the lichen genus Tenuitholiascus (Jiang et al. 2020) .