E-Flora BC: Electronic Atlas of the Flora of British Columbia

Species description:
Genus name apparently derived from the blunt operculum; the species name referring to the creeping shoots.

Reproduction:
Sporophytes frequent and often abundant, maturing in spring to early summer; sporophyte reddish brown or with sporangium green and curved when immature.

Distinguishing characteristics:
The slender, soft plants with leaves show­ing an inconspicuous single midrib are usually sufficient to distinguish this species, especially if it occurs on wood.

Habit:
Reclining slender dark green to reddish-brown, thread-like stems forming interwoven mats, somewhat glossy (under lens); not changing markedly from moist to dry conditions, except that the leaves diverge outward when wet and are against the stem when dry.

Similar Species:
If on rock or soil, several genera might resemble it. Most require examination of microscopic features for discrimination: A. compactum has sharp teeth at the leaf base while A. serpens lacks them; Heteroc/adium macounii has papillose leaf cells when viewed under a com­pound microscope; most Campylium species that are the same size as the Amblystegium have leaves more spread when wet or dry; Kindbergia praelonga, when small, has a strong midrib in the leaves; Isothecium stoloniferum has toothed leaves, even in the slender forms of the size of A. serpens.