Marchantia polymorpha aka Common Liverwort

Marchantia polymorpha has two common names: common liverwort and umbrella liverwort. It is part of the Marchantiaceae family. NC State gives its range as worldwide. This small plant looks like moss and spreads flat over soil. Its mats may look leafy, but they lack leaves. Its body, called a thallus, has no true stems or roots. Small parts called rhizoids hold it to the soil. It lacks tissues that move water and food through flowering plants.

This plant makes no flowers or fruit. It spreads by spores and small bodies called gemmae. Wind blows the spores away from the parent plant. The gemmae grow in small cups on the thallus. Rain or water used on plants splashes them onto nearby ground. It spreads this way more often than by spores. Both ways help it reach new patches of soil. It grows fast and has a spreading form.

Cool, damp sites suit this plant. It grows in deep shade and takes partial shade too. It can grow and breed under man-made light. Its soil can stay moist or turn wet at times. Sites used to raise new plants often get water. This helps explain why it grows in those sites. It also grows among herbaceous perennials that get water on a set schedule. These plants live for years and lack woody stems. But too much water can lead to disease. The sources give no size at full growth or hardiness zones.

In gardens and nurseries, this plant can be a tough weed. New plants brought to a site may carry it. Checks on new plants can catch patches before they spread. Control may mean pulling it by hand more than once. It may also mean changing the way plants grow. NC State says mulch and some weed killers can curb it. That source says it needs much work to manage. This means weed control, not trouble keeping the plant alive.

The plant also has value on bare ground people have disturbed. It can be among the first plants after fire. Its cover helps keep soil in place as the soil improves. It copes with high soil levels of lead and other heavy metals. This may help restore damaged sites. Fungus gnats, springtails, slugs, and snails can cause trouble. Slime molds and diseases from bacteria or fungi may occur too. Past use for liver ills does not prove health benefits. The evidence does not show whether it is safe to eat or toxic.