Gymnomitrion obtusum

Gymnomitrion obtusum
Phylum: Marchantiophyta
Family: Gymnomitriaceae
Genus: Gymnomitrion
Common NameBlunt frostwort
FrequencyFrequent
© John Reynolds
iNaturalist
© Brian Starzomski
iNaturalist
© Randal Mindell
iNaturalist

Distinguishing Features

Thriving on vertical rock faces, G. obtusum presents itself in dense tufts of downtrending white, wormy shoots up to 1 mm wide by centimeter(s) long. With a hand lens you should be able to make out individual bilobed leaves tightly overlapping one another on all sides (“imbricate”). The tips of the lobes in this species are rounded, the lobes themselves joining about 1/3 down the length of the leaf in a sinus that is sharply-angled.

Similar species

The only other white-hued liverworts in the region belong to the genus Anthelia, which is an order of magnitude smaller. While A. julacea and A. juratzkana can occur in similair alpine environments and show tightly overlapping leaves, the leaves are deeply divided (more than 2/3rd their length) compare to species of Gymnomitrion, which are typically divided to about 1/3rd their length. See table for comparison to other regional species of Gymnomitrion.

Habitat

Dry to moist, usually sheltered cliffs, rock faces, ledges, crevices, boulders, and soil (rare) in the lowland, montane, and subalpine zones

Associated species

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Distribution Map

Relevant Literature