Scapania mucronata
Marchantiophyta
Scapania mucronata (Scapaniaceae)
Sharp Earwort
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Rare
Distinguishing Features
Scapania mucronata is a rare species of rock, soil and wood with small, green to brown leafy shoots (<3 mm wide x <12 mm long). With a hand lens, you should be able to make out 3 key features: (1) the elongate aspects of the unequal upper and lower leaf lobes (2) the point of convergence between the two lobes ("the keel") is gently rounded, not sharply folded and (3) The presence of a sharp point at the tip of the lower lobe (see photo). The plant is often laden with green, asexual repoductive bodies ("gemmae") that are two-celled in under the microscope.
Similar species
The combination of a rounded keel and pointed tip on the lower leaf lobe makes this small species hard to confuse with any other Scapania with the exception of S. apiculata, a plant found exlusively on decaying wood to which S. mucronata is almost macroscopically identical. The upper leaf lobe in S. apiculata is one-half as wide as it is long, while the upper leaf lobe in S. mucronata is roughly greater than two-thirds as wide as it is long. Furthermore, the gemmae, when present and examined under the microscope, are one-celled in the former species and two-celled in the latter.
Habitat
Moist to wet humus, mineral soil, rock outcrops, boulders, cliffs, decayed wood, seepage areas, and streambanks in the lowland and montane zones
Associated species
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