The branches are densely covered in small leaves, homomallous, constricted at their bases and easily detached.

[1] M. tanianum grows in shady habitats and is mostly epiphytic, commonly found on tree trunks and bark, trunks of tree ferns and Pandanus, and on cliffs.

[1] The species is found in montane rain forest on the Huon Peninsula in northeastern New Guinea, 1100 to 2900 meters.

Specimens have been collected in a range of habitats, including undisturbed very wet montane rain forest, second-growth and badly-disturbed rain forests, disturbed groves of Pandanus, open rainforests on ridge crests, and in rain forest patches surrounded by open Miscanthus grassland.

[1] The plant is named for Dr. Benito C. Tan, a bryologist and expert in tropical mosses.