Plants small to medium-sized, dull. Stems prostrate or pendent; rhizoids from clusters of initials abaxial to leaf insertions, not or weakly branched; axillary hairs 240–360 µm. Leaves distant proximally, crowded distally, oblong-lanceolate to lanceolate, keeled, conduplicate; margins sometimes narrowly reflexed, entire or serrulate proximally, serrulate to serrate at apex; apex obtuse to acute; costa subpercurrent to percurrent; alar cells quadrate or rectangular, slightly enlarged, walls firm; medial laminal cells rhomboidal, linear-rhomboidal, or elongate. Perigonia lateral in leaf axils. Perichaetia with leaves elongate, sheathing setae. Seta 0.7–1.5 mm. Capsule immersed, oblong-cylindric to oval; annulus massive; operculum long-conic or occasionally obliquely rostrate; endostome trellis imperfect. Calyptra cucullate, covering only operculum. Spores 13–18 µm.

Distribution

c, se United States.

Discussion

Species 1.

Brachelyma is semi-aquatic; as with many semi-aquatic mosses, the plants can be slender to almost robust. Distinctive features include long, narrow, keeled-conduplicate, sometimes obscurely bordered leaves; strong, single costae; firm-walled, non-bulging alar cells; serrate to serrulate distal leaf margins; often rhomboidal distal laminal cells; long, sheathing perichaetial leaves, and short setae with completely immersed capsules. Curiously, the surface cells of the setae are quadrate to oblate; the result of simple cell elongation in these cells would give the Brachelyma setae the same length as the Dichelyma setae, as well as immersed or exserted capsules.

Selected References

None.

Lower Taxa

Brachelyma subulatum