The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information. The division name was derived from the genus name Marchantia, named by French botanist Jean Marchant after his father.
Marchantiales is an order of thallose liverworts that includes species like Marchantia polymorpha, a widespread plant often found beside rivers, and Lunularia cruciata, a common and often troublesome weed in moist, temperate gardens and greenhouses.
Marchantiopsida is a class of liverworts within the phylum Marchantiophyta. The species in this class are known as complex thalloid liverworts. The species in this class are widely distributed and can be found worldwide. Complex oil bodies are only found in the gametophyte.
Metzgeriales is an order of liverworts. The group is sometimes called the simple thalloid liverworts: "thalloid" because the members lack structures resembling stems or leaves, and "simple" because their tissues are thin and relatively undifferentiated. All species in the order have a small gametophyte stage and a smaller, relatively short-lived, spore-bearing stage. Although these plants are almost entirely restricted to regions with high humidity or readily available moisture, the group as a whole is widely distributed, and occurs on every continent except Antarctica.
Cavicularia densa is the only species in the liverwort genus Cavicularia. The species was first described in 1897 by Franz Stephani, and is endemic to Japan, where it grows on fine moist soil.
Treubiaceae is a family of liverworts in the order Treubiales. Species are large and leafy, and were previously classified among the Metzgeriales.
Phycolepidozia exigua is a species of liverwort in the family Cephaloziellaceae. It was thought to be the only species in the genus until a new species from India, Phycolepidozia indica, was found in 2014. Phycolepidozia exigua is endemic to Dominica, where it is critically endangered. Its natural habitat is subtropical or tropical moist lowland forests.
Blasiales is an order of liverworts with a single living family and two species. The order has traditionally been classified among the Metzgeriales, but molecular cladistics suggests a placement at the base of the Marchantiopsida.
Apotreubia is a genus of liverworts in the family Treubiaceae. There are two species, Apotreubia nana, which is found in subalpine New Guinea, and Apotreubia pusilla, which has a disjunct distribution between eastern Asia and British Columbia.
Treubia is a genus of liverworts in the family Treubiaceae. There are seven species, all of which are restricted to the southern hemisphere. Five of the species occur in Australasia and the other occurs in Chile. All species are dioicous, with separate male and female gametophytes.
Makinoa crispata is the only species of liverwort in the genus Makinoa and family Makinoaceae. The genus Verdoornia was formerly included in this family, but has been transferred to the family Aneuraceae on the basis of recent cladistic analysis of genetic sequences.
Ptilidium is a genus of liverwort, and is the only genus in family Ptilidiaceae. It includes only three species: Ptilidium californicum, Ptilidium ciliare, and Ptilidium pulcherrimum. The genus is distributed throughout the arctic and subarctic, with disjunct populations in New Zealand and Tierra del Fuego. Molecular analysis suggests that the genus has few close relatives and diverged from other leafy liverworts early in their evolution.
Neotrichocoleaceae is a family of liverworts in order Ptilidiales. It is closely related to the genera Ptilidium and Herzogianthus.
Petalophyllaceae is a family of liverworts in the order Fossombroniales. Most species are thallose; that is, the plant is not differentiated into root, stem, and leaf. The thallus is typically small and bears lamellae on its dorsal surface that give it a ruffled, leafy appearance.
Phymatoceros is the only genus in the hornwort family Phymatocerotaceae and order Phymatocerotales. It includes only two species.
Riella is a genus in the liverwort family Riellaceae, and includes about eighteen species. Plants in the genus are small and grow submerged in shallow temporary pools. Although the genus is widely distributed in the Northern Hemisphere, locating populations is often difficult. Its occurrence is sporadic and local, and the tiny plants are ephemeral. The ornamented spores remain viable for several years, allowing the plants to survive annual drying of their habitat. The plants are easily grown in laboratory cultures.
Petalophyllum, or petalwort, is a genus of liverworts in the order Fossombroniales.
Petalophyllum americanum, common name petalwort, is a species of liverwort in the order Fossombroniales. It is endemic to the Gulf Coast of the United States in Arkansas, Louisiana, Mississippi, and Texas. It was first described as the European species Petalophyllum ralfsii in 1919, but a detailed study later showed that the North American form is a distinct species.
Polytrichastrum formosum, commonly known as the bank haircap moss, is a species of moss belonging to the family Polytrichaceae.
Monoclea forsteri is one of the two species in the thallose liverwort family Monocleaceae. It is dioicous with the capsule dehiscing with a single longitudinal slit. Endemic and widely distributed throughout New Zealand, it is also the country's largest thalloid liverwort. Hooker described the species in 1820. The holotype is in the British Museum.
