Pallavincia lyellii (Hook

Pallavincia lyellii (Hook.) Carruth.

I am writing this document on liverworts, not to be confused with liver spots or liverwurst. According to a dictionary definition a liver spot is a brownish pigmentation found in the skin of older people. Liverwurst is a sausage made of ground liver. Liverworts, of the class Hepaticopsida, are small, non-vascular plants. Their thallus leaves that are only one cell thick help to classify liverworts. These cells have many small chloroplasts. Some of the thalli have polygonal markings, much like the cross section of an animal’s liver. Due to these markings liverworts were once thought to help with ailments of the liver and hence received the name liverwort. Alas, not many bryophytes have been found to have any medicinal purpose let alone cure liver problems.

I’d like to focus now on a particular liverwort, Pallavicinia lyellii. It can be identified by its bright green, narrow, ribbon-like thallus. It is unlobed and sometimes wavy at the edges with a very well defined mid-rib. Male plants have a row of antheridia, which are protected by overlapping, green-toothed scales on each side of the mid-rib. Female plants are larger than the male and have groups of archegonia surrounded by green, laciniate scales directly on the mid-rib. There is a tubular perigynium (with ciliate) that grows up around the sporophyte. Spores are shed any time between April and June.

First found in England, Pallavicinia lyellii likes to grow on wet humus in swamps consisting of hardwood trees. This liverwort can be found in North America as far north as Newfoundland and Minnesota to as far south as Florida.

References

Conrad, H.S. and Redfearn P.L. How to Know the Mosses and Liverworts. 2^nd ed. Wm.

C. Brown Company Publishers. Dubuque, Iowa. 1979.

Crum, Howard. Liverworts and Hornworts of Southern Michigan. The University of Michigan Herbarium. Ann Arbor, Michigan. 1991.

Acknowledgments:

I’d like to thank my friend Leslie for going to the swamp with me. If it wasn’t for her I’d still be there with my hair tangled in that Rosa multiflora bush. I’d like to thank that dude at Kmart for helping pick out my camera and the right batteries and the right kind of film. And I’d like to thank Aurea for helping me scan my pictures.

Written by Amy McClintic
May 2001

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