Macromitrium flavopilosum R. S. Williams 1911

Macromitrium flavopilosum R. S. Williams,
Bull. Torrey Club 38: 34. 1911.
Plants in rather loose mats with bare or tomentose creeping stems ; secondary stems rather distant, robust, up to 2 cm. high, often somewhat divided; leaves crowded, spreading-flexuous, slightly undulate, the upper 8-9 mm. long, narrowly lanceolate, smooth on both sides, gradually or abruptly tapering into a long, smooth hair-point %-% the length of the blade, the margins plane and serrulate above; all leaf-cells incrassate, elongate, the upper oblong, 10-20 fx long, 2-5 times as long as broad, the lower narrowly linear, narrower at the margins, smooth or with a few low, broad papillae; perichaetial leaves not much different but apt to be more abruptly narrowed to the hair-point, their upper cells shorter instead of longer; pseudautoicous; seta smooth, about 1 cm. long; capsules obovoid, the urn scarcely 2 mm. long, smooth; calyptra without hairs, rough at the apex; operculum convex, the beak slender, straight, % the length of the urn ; peristome double, papillose, the outer a low cylinder with an irregular margin, the inner a little higher; spores up to 30 n in diameter.
Type locality: Cana, Province of Darien, Panama {Williams 1063 in herb. N. Y. Bot. Gard.).
Distribution: Known only from the type locality. .... , ., , , .