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Marchantia, an example of a liverwort (Marchantiophyta) An example of moss (Bryophyta) on the forest floor in Broken Bow, Oklahoma. Bryophytes (/ ˈ b r aɪ. ə ˌ f aɪ t s /) [1] are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses. [2]
The evolution of plants has resulted in a wide range of complexity, from the earliest algal mats of unicellular archaeplastids evolved through endosymbiosis, through multicellular marine and freshwater green algae, to spore-bearing terrestrial bryophytes, lycopods and ferns, and eventually to the complex seed-bearing gymnosperms and angiosperms ...
This second feature is the origin of the term 'embryophyte' – the fertilized egg develops into a protected embryo, rather than dispersing as a single cell. [17] In the bryophytes the sporophyte remains dependent on the gametophyte, while in all other embryophytes the sporophyte generation is dominant and capable of independent existence.
The evidence of plant evolution changes dramatically in the Ordovician with the first extensive appearance of embryophyte spores in the fossil record. The earliest terrestrial plants lived during the Middle Ordovician around 470 million years ago , based on their fossils found in the form of monads and spores, with resistant polymers in their ...
By contrast, mosses and other bryophytes have only a single set of chromosomes and so are haploid (i.e. each chromosome exists in a unique copy within the cell). There is a period in the moss life cycle when they do have a double set of paired chromosomes, but this happens only during the sporophyte stage.
Bryophytes have life cycles that are gametophyte dominated. The longer lived, more prominent autotrophic plant is the gametophyte. The sporophyte in mosses and liverworts consists of an unbranched stalk (a seta) bearing a single sporangium or spore-producing capsule. Even when capable of photosynthesis, as in mosses and hornworts, bryophyte ...
The fossil history of flowering plants records the development of flowers and other distinctive structures of the angiosperms, now the dominant group of plants on land.The history is controversial as flowering plants appear in great diversity in the Cretaceous, with scanty and debatable records before that, creating a puzzle for evolutionary biologists that Charles Darwin named an "abominable ...
Marchantiales is an order of thallose liverworts (also known as "complex thalloid 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.