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

Species description:
Genus name derived from a Greek word meaning sleep, apparently reflecting the ancient use of some mosses as medicinal ingredients. Species name describing the strongly curved leaves.

Reproduction:
Sporophytes frequent, maturing in late winter to early spring; the small stout sporangia are characteristic.

Distinguishing characteristics:
The short, stout, inclined, red-brown spo­rangia, associated with the pale glossy green, creeping shoots with facate-secund to strongly curved leaves that have attenuate tips and lack a midrib, usually separate this species.

Habit:
Forming glossy, pale green to yellow-green mats or rarely, turfs.

Similar Species:
H. subimponens often grows in similar habitats but the plants are larger, more regularly branched and the sporangia are sub­erect and cylindric. Some forms of Drepanocladus uncinatus also occur in the same habitats, but the leaves have a midrib and the sporangium is cylindric and usually curved. Pseudotaxiphyllum elegans may resemble H. circinale, but the plants are usually terrestrial, the shoots are somewhat flattened, and sporophytes, although not common, are clearly nodding.