Macromitrium altituberculosum

Macromitrium altituberculosum E. Bartr.;
Grout, Bryologist 47: 17. 1944.
Plants rather robust, in wide mats, dull olive-green, brown below; branches crowded, about 1 cm. high, obtuse, densely foliate, reddish-tomentose below; leaves appressed and spirally contorted when dry, spreading when moist, about 2 mm. long by 0.8 mm. wide, Ungulate, concave, plicate, obtuse, short-mucronate, decurrent, the margins erect, crenulate above, tuberculate-toothed toward the insertion; costa strong, short-excurrent ; upper leaf-cells rounded-hexagonal, not incrassate, 6-7 a* in diameter; basal cells narrowly rectangular, strongly tuberculate, at the decurrent basal angles densely armed with long spine-like tubercles; perichaetial leaves similar but acute, the costa percurrent; seta stout, 6 mm. long, smooth; capsules ovoid, the urn 2 mm. long, strongly ribbed when dry; calyptra naked, scabrous above, 3.5 mm. long; operculum 1-1.2 mm. long, conic-rostrate; peristome simple, the teeth to 240^ long, densely and minutely papillose; spores papillose, to 30 p. in diameter.
Type locality: Guatemala, Sierra de las Minas, Dept. Zacapa, in oak-pine woods along the upper reaches of Rio Sitio Nuevo, between Santa Rosalia and first waterfall, on rock, alt. 1200-1500 m. (Steyermark 42274).
Plate 4. /. 25-30.
Distribution: Known only from the type locality.