Dale H. Vitt
Macromitrium sect. Macrocoma J. K. A. Müller
Plants slender to filiform, mats on trees and rocks. Stems creeping with numerous lateral ascending branches. Branch leaves closely erect-appressed, not contorted when dry, erect-spreading when moist, up to 2 mm, lanceolate to ovate-lanceolate, narrowly obtuse, acute, or bluntly acuminate, carinate, rhizoids often produced on the abaxial side of the costa; margins ± plane, entire; costa percurrent, prominant; distal cells small, rounded-quadrate, bulging, smooth or papillose; basal cells rounded to elliptic, bulging, papillose-mammillose. Perichaetial leaves slenderly acute. Sexual condition goniautoicous. Seta smooth, to 7 mm, dextrose. Capsule exserted, oblong-cylindric to fusiform, ± plicate above or smooth; stomates superficial; peristome single or lacking; consisting of 16 pale, short, blunt teeth or a low, papillose membrane. Calyptra mitrate, long elliptic-conic, ± hairy, completely covering capsule, smooth. Spores rather large, isomorphic.
Species 11 (1 species in the flora); in higher elevation scrub forests; North, Central and South America, West Indies, Asia, Africa (including Madagascar), Australia, Pacific Islands (Hawaii, New Zealand).
In addition to the rounded basal cells, characters of the genus include the slender, irregularly branched stems, leaves erect-appressed when dry, capsule cylindric, peristome often reduced, and calyptra long conic-elliptic.