[Amphoridium rupestre (Lindb. ex C. Hartm.) De Not., moreZygodon baumgartneri Malta, Zygodon viridissimus f. rupestris (Lindb. ex C. Hartm.) Malta, Zygodon viridissimus subsp. rupestris Kindb., Zygodon viridissimus var. rupestris (Dicks.) Brid., Zygodon viridissimus var. vulgaris Malta, Zygodon vulgaris (Malta) Nyh.]
Plants: to 2.3 cm, yellow-green, olive green, or brownish. Stem: leaves linear- to elongate-lanceolate; margins entire; apex short-acuminate or apiculate. : Specialized asexual reproduction by elliptic gemmae, of 3–5 cells, longitudinal septa absent.
Trunks of trees, rock. low to moderate elevations. Alta., B.C., N.B., N.S., Ont., Que., Ariz., Calif., Mass., Mich., Mo., N.Mex., N.Y., N.C., Oreg., Tenn., Va., Wash., Wis., Mexico, Europe, n Asia, n Africa. Discussion.