Homotypic Synonyms See Note

Basionym Name:
Placodium argillaceum C. Knight, Trans. Linn. Soc. London, Bot., Ser. 2 1(5): 282 (1878)

Homotypic synonyms:
Lecanora argillacea (C. Knight) Forssell, Flora, Regensburg 72: 366 (1889)
Lecanora argillacea f. argillacea (C. Knight) Forssell, Flora, Regensburg 72: 366 (1889)
Lecanora rhodomma f. argillacea (C. Knight) Zahlbr., Cat. Lich. Univers. 5: 670 (1928)
Lecanora rhodomma var. argillacea (C. Knight) Nyl. ex Hue, Nouv. Arch. Mus. Hist. Nat., Paris, 3 sér. 3: 59 (1891)
Lecanora rhodophthalma f. argillacea (C. Knight) Zahlbr., Cat. Lich. Univers. 5: 670 (1928)
Placopsis argillacea (C. Knight) Malcolm & Vězda, in Vězda, Lichenes Rariores Exsiccati, Fasc. 34(nos 351-340): no. 340 (1997)
Placopsis parellina f. argillacea (C. Knight) I.M. Lamb, Lilloa 13: 251 (1947)