Orthotrichum speciosum var. roellii Venturi
Plants 5--22 mm. Stem leaves stiffly flexuose when dry, wide-spreading when moist, lanceolate to narrowly lanceolate, 2.3--3 mm, broadly acuminate to acute, margins strongly revolute nearly to apex, entire; distal laminal cells 8--10 µm wide, 1-stratose, with small conical papillae; basal laminal cells elongate, nodose. Sexual condition autoicous. Seta 1--2 mm. Capsule smooth, erect, emergent to sometimes shortly exserted; urn small and narrow, narrowly cylindric to fusiform-cylindric, 1.3--2 mm, smooth; stomates superficial; peristome double; endostome segments 8, 2 rows of cells, coarsely papillose; exostome teeth 8, recurved, coarsely papillose. Calyptra conic-oblong, sparsely hairy. Spores 13--26 µm.
Deciduous trees, especially Populus species; occasionally conifers; 200--1000 m; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask.; Alaska, Maine, Mass., Mich., Minn., Mo., N.H., N.J., N.Y., Ohio, Pa., R.I., Vt., Wis.; Europe; Asia.
The small plants forming a rather compact tuft are quite different from the larger, loosely tufted plants of O. speciosum. Orthotrichum elegans also has fusiform-cylindric, totally smooth, and emergent to shortly exserted capsules while O. speciosum has long-cylindric, generally lightly 8-ribbed, fully exserted capsules. Orthotrichum striatum has 16 exostome teeth and endostome segments.