Liverworts are classified as bryophytes with mosses and hornworts. There are over 8000 liverwort species that are widely distributed on the planet. Most prefer a moist environment, but there are a few that exist in dryer climates and there are aquatic species as well. The name was derived from their round, liver-shaped “leaves” which grow long, low and flat.
Bryophytes are considered to be the simplest of all plants. They do not have true roots, leaves, or stems, and they lack tissues (such as xylem and phloem) that would allow them to retain water or transport water to various parts of the plant. Instead, they gain their nutrition through photosynthesis. Instead of producing flowers which then seed, bryophytes reproduce sexually with spores that are transported by water or asexually by division. Hair-like appendages called rhizoids (much shorter than roots) anchor the plant to its substrate (soil, damp rocks, or tree trunks in deep woods).
Because of their small size and ability to grow where other plants cannot, liverworts have been around for a long time. An ancient liverwort fossil found in Argentina rock is believed to be 471 to 473 million years old.
Thanks to Jim Hinds who was able to narrow the species to Frullania – either F. eboracensis or F. asagrayana based on information and photos from Liverworts of New England, by Mary S. G. Lincoln.