Macromitrium fusco-aureum E. B. Bartram 1928

Macromitrium fusco-aureum E. Bartr Contr. U. S. Nat. Herb. 26: 83. 1928.
M
Secondary stems robust, in dense tufts up to 6 cm. long, not radiculose, reddish-brown below, lurid yellowish-green above; leaves widely flexuous-spreading and somewhat contorted when dry, abruptly squarrose-spreading from an erect, plicate, clasping base when moist, 8-10 mm. long, narrowly linear-lanceolate, gradually narrowed to a long hair-point consisting mainly of the strongly dentate, excurrent costa and up to J^ the length of the leaf, the basal margins recurved, the upper plane and serrulate ; leaf-cells all elongate, smooth, the upper 25-40 fi long, their lateral walls incrassate, pitted, as broad as the lumen, gradually elongate to the much longer, somewhat colored basal cells; probably dioicous; seta 2 cm. long; capsules cylindric, 2 mm. long; peristome and spores not seen.
Type locality: On trees, Cerros de Zurqui, northeast of San Isidore Province of Heredia, Costa Rica, alt. 2000-2400 m. (Standley & Valerio 50493; type in herb. Bartram examined).
Distribution: Known only from the type locality.

Macromitrium fusco-aureum là một loài rêu trong họ Orthotrichaceae. Loài này được E.B. Bartram mô tả khoa học đầu tiên năm 1928.