Macromitrium swainsoni

Macromitrium swainsoni (Hook.) Brid
Bryol. Univ. 1:318. 1826.
Orthotrichum Swainsoni Hook. Musci Bxot. pi. 127. 1820.
Secondary stems 5-10 mm. long, branching; leaves appressed and contorted when dry, erect-open when moist, 1.5-2 mm. long, oblong-lingulate to ovate, longitudinally plicate, rugose, the margins plane, entire; costa strong, percurrent to excurrent into a short mucro; leafcells all incrassate, the upper quadrate to rectangular, rounded, some almost circular, the others transversely elongate, more elongate and larger near the costa, still larger and longer at the base, up to 40 X 7 m, the walls pitted; perichaetial leaves less plicate, more membranous; seta smooth, up to 1 cm. long ; capsules ovoid, smooth (according to Hooker) or plicate (according to Mitten); calpytra hairless, deeply mitrate; operculum long-rostrate; columella longexserted; peristome simple, of pale, linear, slender teeth, papillose, up to 0.3 mm. long, with a distinct median line, often split at the apex; spores papillose, up to 30 /* in diameter.
Type locality: Bahia, Brazil (W. Swainson) . m
Distribution: On trunks and the branches of trees; Cuba; Mexico {Pringle 767); Guatemala