Jungermanniidae

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Jungermanniidae
Lophozia ventricosa

Lophozia ventricosa

Systematics
without rank: Phragmoplastophyta
without rank: Streptophyta
Empire : Plants (Plantae)
Department : Liverworts (Marchantiophyta)
Class : Jungermanniopsida
Subclass : Jungermanniidae
Scientific name
Jungermanniidae
Engl.

The Jungermanniidae are a subclass of the liverworts and include the leaved liverworts (with the exception of Pleurozia ). With around 4,300 species, they are the most species-rich group of liverworts.

features

The moss plants are prostrate, ascending or upright, rarely hanging. They are monosymmetrical or anisophyll or isophyll. The gametophyte grows with a tetrahedral apex cell . A few taxa such as butcher's iopsis are secondarily thallous . The stems do not have a central strand. Rhizoids are mostly present and predominantly unicellular.

The leaflets are usually only one layer of cells thick, a midrib is missing. The basic shape of the leaflets is bilobed, they can also be three to multiple lobes or deeply divided into thread-like segments, or undivided. Usually they form two rows of lateral leaves and "sub-leaves" or amphigastria. The latter are smaller than the lateral leaves. The shoots are mostly flattened, the leaves overlap either overshot or undershot. The cells containing chlorophyll contain oil bodies .

The reproductive organs arise from surface cells on the trunk or on the side axes. The antheridia are in the axils of bracts, on the main shoot or on special male branches. The archegonia are protected by bracts or bracts and are terminal on the main shoot or on side branches (acrogynous).

The growing sporophyte is usually protected by a tubular perianth, which is formed from two to three overgrown leaves. The seta is usually very short until it is ripe, then it is often considerably extended within a few days. The mature capsules are spherical to cylindrical, their walls are two to ten cell layers thick. They open with four flaps. The elaters are unicellular and free, in some Lejeuneaceae and Jubulaceae they are connected to the capsule wall.

The spores germinate into a very small, thaleless protonema . A single moss plant emerges from a protonema.

The main chromosome number is n = 9, but n = 6, 8, 10, 16, 18, 20, 27, and 36 also occur.

Locations

Many representatives grow epiphytically (on plants) or epilithically (on rocks). In the tropics, many species grow as epiphylls on the leaves of trees, shrubs and ferns in shady forests with high humidity. The Jungermanniidae reach their highest biodiversity in the tropical cloud forests and in the temperate rainforests. Very few species grow in arid locations.

Systematics

The Jungermanniidae are the sister group of the Metzgeriidae . They themselves form two main clades, which are classified as superordinates.

The Jungermanniidae are subdivided as follows, although the classification is not yet considered final:

Fossil history

The Jungermanniidae are absent in the Paleozoic , but a possible representative is Jungermannites keuperianus from the Upper Triassic. The oldest safe representative is Jungermannites gracilis from the Jungermanniales from the Middle Jura of the Antarctic. The early diversification is likely to have occurred in Gondwana . In the amber inclusions (Baltic States, Bitterfeld, Dominican Republic, Mexico; Eocene to Miocene ) the Jungermanniidae are the only representatives of liverworts. The great biodiversity and diversification took place as a co-evolution with the evolution of angiosperms and the formation of the tropical rainforests.

Individual evidence

  1. ↑ a b c d e f g Wolfgang Frey, Eberhard Fischer, Michael Stech: Bryophytes and seedless Vascular Plants . In: Wolfgang Frey (Ed.): Syllabus of Plant Families - A. Engler's Syllabus of Plant Families . 13th edition. tape 3 . Borntraeger, Berlin / Stuttgart 2009, ISBN 978-3-443-01063-8 , pp. 43 ff .