| Latin name: Marchantia polymorpha |
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| Phylum: Hepatophyta Class: Marchantiopsida |
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| Common name: Liverwort |
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Habit: Dense, fleshy mat that
grows prostrate over the surface of container crops and/or greenhouse
and nursery floors. |
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Foliage: The leaf-like structure
that covers the surface of the ground or container are called
thalli
(thallus in singular form). Liverworts are not vascular plants, but
a more primitive life form similar to mosses. They do not
have true leaves like most organisms we consider plants. |
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Flower: Liverworts do not
have flowers (and thus do not produce seed), instead they archegoniophores
and antheridiophores (female and male sex organs). Liverwort
are unisexual, with male and female sex organs forming on
different plants. Antheridiophores
look like an umbrella while the female achegoniophores have
finger-like
projections.
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| Seed: Liverworts reproduce
sexually by spores, not seed. Liverworts can also reproduce asexually
by gemmae (see section on foliage above). |
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Roots: Marchantia do not have
roots, they have rhizoids which are root-like structures that lack xylem
and phloem. |
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Related species: Lunularia cruciata, which is another liverwort similar in appearance to Marchantia. |
| Special considerations: The
term liverwort refers to a group of about 6,000 species. Only one,
Marchantia polymorpha, is a weed problem in nurseries. Are
we giving all liverworts a bad rap because of one species? It seems
so. (Observation made by Sven Svenson, Oregon State University) |
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Liverwort control: Liverwort cannot be controlled by herbicides alone. Cultural practices must be implemented that complement herbicides. |
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Postemergence Control: Evaluate our postemergence liverwort control trials. In these trials, we used only products currently labeled, or those for which the manufacturer is pursuing a label.
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Preemergence Control: Evaluate 2003 container herbicide trials at Oregon State University |