Brachythecium campestre

Plants medium-sized to large, in moderately dense mats, light green, yellow-green, or whitish stramineous. Stems to 7 cm, creeping, terete-foliate, irregularly pinnate, branches to 8 mm, straight to slightly curved, terete-foliate. Stem-leaves erect, loosely appressed, loosely imbricate, narrowly ovate-triangular or ovatelanceolate, broadest at 1/9–1/7 leaf length, sometimes almost at costa insertion, concave, plicate, plicae usually parallel in falcate leaves, often shallow and uneven in straight leaves, giving some leaves a crumply appearance, 1.5–2.6 × 0.5–1.2 mm; base rounded, broadly short-decurrent; margins partly plane, recurved in many places, serrulate to serrate in acumen, occasionally almost entire, variable within one shoot; apex gradually tapered or acuminate; costa to 40–70% leaf length, moderately strong, small terminal tooth sometimes present; alar cells subquadrate or short-rectangular, same size as or smaller than basal-cells, 15–25 × 11–13 µm, walls thick, region ± clearly delimited, 4–9 × 4–7 cells; laminal cells linear, (30–) 60–100 (–110) × 6–9 µm; basal-cells to 20–40 × 10–15 µm, region in 1–3 rows, not markedly different from more distal cells. Branch leaves often falcate-secund; alar region conspicuous, pellucid, triangular. Sexual condition autoicous. Seta orangebrown to dark-brown with age, 2–2.5 cm, rough or occasionally smooth. Capsule inclined to horizontal, dark-brown, elongate, curved, 2 mm; annulus separating by fragments; operculum conic. Spores 15–19 µm.

Habitat: Soil, wooded areas, limestone, concrete blocks, tree trunks
Elevation: low to moderate elevations (10-500 m)

Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Sask., Conn., Del., Iowa, Maine, Mich., Minn., Mo., N.H., N.Y., R.I., S.Dak., Wis., Eurasia

Discussion

A. J. Grout (1928–1940, vol. 3) and H. A. Crum and L. E. Anderson (1981) expressed some doubts on the status of Brachythecium campestre and its clear differentiation from B. salebrosum. However, B. salebrosum seems absent or at least rare in eastern North America (except probably the more northern regions of eastern Canada). The vast majority of collections referred to B. salebrosum in eastern North America belong to B. acutum, B. campestre, B. rotaeanum, and other species. There are some differences between European and American B. campestre; if further studies provide additional evidence for their separation, then the American populations should be called B. leucoglaucum; for typification of this name and discussion on this species, see M. S. Ignatov et al. (2008). The diagnostic characters of B. campestre include the usually light green to whitish color, ovate-lanceolate leaves that are rather crumply plicate when optimally developed, alar cells in small to large groups of rather small and subquadrate cells, and, usually, a minutely rough seta.

Selected References

None.

Lower Taxa