Orthotrichum Moss

Orthotrichum sordidum Sull. & Lesq.;
Aust. Musci App. 30. 1870.
An eastern species closely related to 0. affine; leaves abruptly acute; seta less than 0.5 mm. long; capsules nearly or quite immersed, ovoid-pyriform, the neck as long as the spore-case, light yellow, rather lightly ribbed, the urn 1.2-1.6 mm. long; exothecial cells only moderately differentiated ; peristome-teeth sometimes remaining erect for a considerable time.
Type locality: Cambridge, Massachusetts.
Distribution: Common on the bark of trees; northeastern United States and southeastern Canada, south to New Jersey.