Montana Field Guide

GROWTH FORM: Leafy.

PLANTS: Tiny liverwort, 0.5-1.0 mm wide, to 8 mm long. Plants are dull greenish.

LEAVES: Transversely inserted, caniculate (trough-shaped) leaves that are bi-lobed.

Sources: Hong 1996; Stotler and Crandall-Stotler 2017.

Most leafy liverworts that grow on logs in conifer forests either lack gemmae or have red-pigmented gemmae or are much larger plants.

Lophozia longidens is the most similar small, red-gemmiferous, log dwelling leafy liverwort. It differs in being about twice as large, with leaves that are cupped at the base, but not trough-shaped along their length, and in having 2-celled gemmae. It is a very common and widespread species. Soderstrom (1993) found Lophozia longidens most often on tree bases rather than rotten logs.

Tritomaria exsecta and Tritomaria exsectiformis have rust-red, 2-celled gemmae, and three-lobed leaves.

Sources: Hong 1996; Hong 2002; Schuster 1969.

On decayed wood in shady forests. Söderström (1993) found it exclusively on wood, largely on rotten logs, occasionally on wood pieces or stumps. Schuster (1969) described habitat as shady forests on logs of intermediate decay (i.e., not freshly fallen and with bark sloughed off and wood not decayed to the point of becoming punky).

Anastrophyllum hellerianum is often found with Jamesoniella autumnalis, Lophozia longidens, Ptilidium pulcherrimum, and Tritomaria exsectiformis (Hong 1996).

Anastrophyllum hellerianum is part of a diverse community of log-dwelling cryptogams in the forest understory. Logs suitable for Anastrophyllum hellerianum (and for most log-dwelling cryptogams) are on or close to the ground where plants can remain moist for longer (Söderström 1993).

Dioicous - separate male and female liverwort plants.

Asexual reproduction is by gemmae. Gemmae are 1-celled, quadrangular, and wine-red and are found on the edges and tips of upper leaves. Gemmae-bearing shoots are usually narrower than non-bearing shoots, often attenuated, and with leaves that become smaller and more appressed toward the tips.

The perianth (a sheath encasing the female reproductive organ) is smooth below but 5-plicate above with spinous, ciliate mouths.

Species-rich, log-dwelling cryptogam (bryophyte and lichen) communities are found in forests with a natural canopy density, but are absent or are species-poor in forests that have regenerated from clear-cut timber prescriptions (i.e., exhibit dog-hair tree stands). Managed forests that are thinned in order to open up the canopy are generally of poor habitat for log-dwelling species because:
* Thinning treatments may crush or turn logs, bypassing the natural slow wood decay process, and
* Opening of the canopy occurs too rapidly, resulting in a sudden increase in light intensity and a sudden decrease in humidity, which may disrupt the species-accumulation and succession process of log-dwelling cryptogam communities.

Shaded, rotting logs do not last forever. For log-dwelling communities to persist here must be other rotting logs that become available while existing substrates degrade. Logs in various decay stages must be available for log-dwelling communities to persist.

In managed forests that retain coarse woody debris, the logs are often heaped in to piles, making them unsuitable for nearly all log-dwelling cryptogam communities. Pohjano and Laaka-Lindberg (2004) stated that Anastrophyllum hellerianum “has declined in recent decades in Finland as a consequence of forestry practices”. Management that can spread out coarse woody debris will provide habitat for log-dwelling bryophytes and lichens. Logs that can contact soil in shady forests will more likely decay and at various rates.

Sources: Hong 1996; Söderström 1993.

Persistance of Anastrophyllum hellerianum requires logs in various stages of decay, which is often scarce or absent in managed forests.

Source: Pohjano and Laaka-Lindberg 2004