Basionym Name:Collema tremelloides var. caesium Ach., Lich. Univ.: 656 (1810)
Homotypic synonyms:Leptogium caesium (Ach.) Vain., Acta Soc. Fauna Flora fenn. 7(no. 1): 225 (1890)Leptogium caesium var. caesium (Ach.) Vain., Acta Soc. Fauna Flora fenn. 7(no. 1): 225 (1890)Leptogium sinuatum f. caesium (Ach.) Arnold, Flora, Regensburg 68: 176 (1885)Leptogium tremelloides var. caesium (Ach.) Hue, Nouv. Arch. Mus. Hist. Nat., Paris, 3 sér. 10: 224 (1898)Lichen tremelloides var. caesius (Ach.) Wahlenb., Fl. Suec. 2: 839 (1826)