Canoparmelia rarotongensis

This lichen has a moderately attached, thin and flexible thallus that can grow up to 6 cm (2.4 in) wide. The lobes are unevenly shaped and connected in the centre, but separate near the tips, measuring 2–4 mm wide. The edges of the lobes are smooth and occasionally wavy, appearing flat, without any cilia. The top surface is a dusty grey-green colour, unevenly cracked in the centre with visible isidia, which are inflated and mostly branched, forming clusters that can be up to 0.5 mm wide and up to 0.8–1 mm high. The medulla is white, while the bottom surface is black and dull, with a narrow brown margin measuring up to 1 mm wide. The rhizines are black, not densely spread, and have a coarse and simple appearance. No apothecia or pycnidia were observed.^[2]

Canoparmelia rarotongensis produces atranorin, chloroatranorin in the cortex and lecanoric acid in the medulla as major lichen products, and trace amounts of orsellinic acid, and orcinol. Before this species, lecanoric acid had not been reported to occur in the genus Canoparmelia. The expected results of standard chemical spot tests are K+ (yellow) in the cortex, and K−, C+ (red), PD− in the medulla.^[2]