Porella spp.

porella liverworts

Northern Hemisphere and beyond (humid woodland)

Native to North America

SunPart Shade – Full Shade

Overview

Porella spp. is a genus of robust leafy liverworts in the family Porellaceae, growing on rock, tree bark, and soil in shaded, humid places across much of the world. The creeping, much-branched shoots are 1-4 inches (2.5-10 cm) long and grow flattened against the surface in overlapping mats, deep green to olive or brownish. Each shoot bears three ranks of leaves: two rows of larger main leaves, each folded so a small lobe tucks beneath, and a row of underleaves pressed along the stem underside, a three-part arrangement typical of the genus. The leaves are rounded and untoothed in most species, giving a neat, regular pattern. Some species, such as P. platyphylla, carry a peppery taste that deters grazing. Porella spp. favours humid, sheltered habitats such as woodland trees, shaded rocks, ravines, and walls, and is sensitive to air pollution, so its presence indicates relatively clean air. Reproduction is by spores from capsules on short translucent stalks, produced occasionally, with most spread by branching growth and fragments. The flattened, three-ranked, glossy mats make the genus recognisable among leafy liverworts.

Native Range

Porella spp. is widespread across the Northern Hemisphere and beyond, growing on tree bark, shaded rocks, walls, and soil in humid woodland, ravines, and sheltered slopes. It favours clean, humid air and is found from lowland forest to mountains.

Suggested Uses

Porella spp. is grown in humid terraria and on shaded bark and stone in moss gardens for flat green cover, and it serves as an indicator of clean air and humid, undisturbed habitats. The genus is used in bryophyte study and in teaching liverwort leaf arrangement.

How to Identify

Identify by the flattened, glossy, deep green to olive mats of creeping leafy liverwort shoots pressed to bark or rock, with leaves in three ranks: two rows of folded main leaves and a row of underleaves beneath. The regular three-ranked pattern and often peppery taste separate Porella spp. from Scapania spp. and other leafy liverworts.

Appearance

Colors

Foliage Colors

green

Bloom Information

Liverworts do not flower. Porella spp. reproduces by spores from capsules borne on short, pale, translucent stalks, produced only occasionally. Most spread is vegetative, through branching growth and detached fragments that root and grow.

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Water & Climate

Water Needs

Medium

Care & Maintenance

Care Guide

Porella spp. grows on tree bark, shaded rock, and walls in humid, sheltered sites in part to full shade, needing clean, moist air and stable surfaces. It tolerates short dry spells by drying out and reviving when wetted but declines in polluted or very dry air. The genus is occasionally grown in humid terraria on bark and stone. Air pollution, drought, and strong sun reduce it. Established mats enlarge on their own by creeping growth.