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

Species description:
Species name meaning somewhat like imponens, referring to its resemblance to H. imponens The name imponens means imposter, indi­cating that this species strongly resembles, at times, other species of Hypnum.

Reproduction:
Sporophytes frequent, erect to suberect, especially when unripe (green), reddish-brown when ripe.

Distinguishing characteristics:
The yellow-green colour, abundant regular pinnate branching, coupled with the usually non-terrestrial habitat and the erect to suberect sporangia are valuable features.

Habit:
Forming reclining, glossy, pale yellow-green mats of regularly pinnate plants loosely attached to the substratum.

Similar Species:
See notes under H. circinale. Ptilium crista-castrensis is of a similar colour but the plants are very regularly pinnate, tend to be erect to suberect, rather than reclining, and are generally terrestrial within forests. The leaves of Ptilium are pleated, a feature absent in the Hypnum, and shoots of the Hypnum frequently grow with the apex pointing downward rather than consistently upward as in Ptilium. Spo­rangia of Ptilium are strongly inclined.