Mastigobryum heterophyllum Steph., Sp. Hepat. 6: 466. 1924 [nom. illeg., non Colenso 1887], syn. nov.

Holotypus: ECUADOR. Prov. Morona Santiago: Gualaquiza, “in silva ad rivum Salado ad truncorum arboris”, V.1909, Allioni s.n. [Bryo. Levier 6577] (G [G00066890]!) .

= Bazzania gracilis (Hampe & Gottsche) Steph.

Notes. – Bazzania gracilis is a widespread neotropical species characterized by the small plants (1 – 2 mm wide) with strongly caducous, entire to shallowly 2-lobed leaves (GRADSTEIN, 2017). Mastigobryum heterophyllum Steph. is identical to B. gracilis . M. H. Fulford (in sched.) already noted this synonymy, but subsequently published M. heterophyllum as a synonym of B. phyllobola Spruce (FULFORD, 1963).