Pellia is a small but widespread genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of liverworts in the cool and temperate regions of the northern hemisphere. It is classified in order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

  Metzgeriales

Metzgeriales

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...

 and is a member of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

  Pelliaceae

Pelliaceae

Pelliaceae is a family of liverworts with only two genera: Pellia and Noteroclada . The two genera are easily distinguished, not only because they occur in completely separate regions of the world, but because Noteroclada has a leafy appearance, while Pellia is more clearly thallose....

 within that order.

Süsswassertang

Süsswassertang

Süsswassertang is a type of aquarium plant formerly known as "round Pellia" or "round-leaf Pellia". It was long considered to be a liverwort, which it strongly resembles, but in 2009, a molecular phylogenetic study determined that it is, in fact, an fern gametophyte. Further, it is a species of...

, a plant grown submerged in aquaria

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

 was once considered to be Pellia endiviifolia, but is now known to be the indeterminate gametophyte of a Lomariopsis species, a type of fern

Fern

A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

.

Species in Pellia

• Pellia borealis
• Pellia columbiana
• Pellia endiviifolia
• Pellia epiphylla
  Pellia epiphylla
  Pellia epiphylla is a species of thallose liverwort. It occurs in North America, Europe, North Africa and parts of Asia. It grows in patches in damp, sheltered places on neutral or acidic substrates...
  
  
• Pellia megaspora
• Pellia neesiana