Olympic Dichodontium Moss

Dichodontium olympicum Ren. & Card. Rev. Bryol. 19: 74. 1892
Dioicous: male plants very similar to the fertile ones, bearing an inconspicuous, terminal, antheridial bud, with the 1 or 2 inner leaves much shorter than the outer, costate, broadly ovate, with a short, obtuse, rough, darker point, the 5 or 6 antheridia about 0.3 mm. long with few paraphyses: fertile plants in rather compact, dark-green cushions, with stems scarcely 1 cm. high: stem-leaves when dry more or less erect-appressed or incurved, when moist widely spreading, up to about 1.7 mm. long, ovate-lanceolate to nearly oblong-linear with a broad, mostly rounded apex, the margins flat all around and papillose-serrate to a little above the insertion of the leaf; costa stout, nearly percurrent, very rough on both sides, about 60^ wide below, in cross-section near the middle showing 4 guide-cells, stereid-bands above and below, and outer cells strongly differentiated; leaf-cells above obscure, roundish, mostly 6-7 m in diameter, with high papillae on both sides, the cells near the base becoming smooth and oblong or rectangular from the margin of the leaf to the costa, up to 8-12 fi wide and 20-40 i long; perichaetial leaves rather longer than the stem-leaves, with the base more lax: seta 8 mm. long; capsule oblong, about 1.5 mm. long, nodding, somewhat curved and strumose, with obliquely rostrate lid; peristome-teeth dark, lanceolate, with 15-20 articulations, divided about one half down into 2 or 3 forks, more or less vertically striate and minutely papillose: calyptra 1.75 mm. long, entire below, rough in the upper half.
Type locality: Olympic Mountains, Washington. Distribution: Known only from the type locality.