Key to species of Solorina and Pseudosolorina
1a. Lower surface bright orange, containing solorinic acid and averantin	2
1b. Lower surface white or pale brown, without solorinic acid and averantin	3
2a. Thallus with smooth margin, contains two separate photobiont layers	S. crocea
2b. Thallus with sorediate margin, contains a single photobiont layer	S. crocoides
3a. Upper surface gray-brown, with single photobiont layer containing cyanobacteria and chlorophytes	4
3b. Upper surface apple green, with single photobiont layer containing chlorophytes	6
4a. Lacking secondary metabolites	P. hepatizon
4b. Containing secondary metabolites	5
5a. Photobiont layer 20–60 µm in thallus and 12–40 µm in apothecium	P. tenuior
5b. Photobiont layer 70–150 µm in thallus and 60–100 µm in apothecium	P. simensis
6a. Thallus well-developed, 2–6 cm in diam.	7
6b. Thallus small, less than 2 cm in diam.	8
7a. Upper surface pruinose, without external cephalodia	P. parmigera
7b. Upper surface rarely pruinose, with external cephalodia	P. saccata
8a. Thallus less than 0.7 cm in diam., asci 4-spored	P. spongiosa
8b. Thallus 1–2 cm in diam., asci (1-)2-spored	9
9a. Asci 1-spored	P. bispora var. monospora
9b. Asci 2-spored	P. bispora