Bryidae

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Bryidae
Ctenidium molluscum

Ctenidium molluscum

Systematics
without rank: Streptophyta
Empire : Plants (Plantae)
Department : Moss (Bryophyta)
Subdivision : Bryophytina
Class : Bryopsida
Subclass : Bryidae
Scientific name
Bryidae
Engl.

The Bryidae are the largest subclass of the mosses (Bryophyta).

features

The protonema of the Bryidae is always a network of cell threads. The leaves are arranged in a spiral (only in exceptional cases with 2, 3 or 5 lines). They have rhizoids . There are paraphyses in the antheridia and archegonia stands . There are also paraphylls and pseudo- paraphylls .

The sporophyte is characterized by the presence of a peristome and a hollow cylindrical archespor in the sporogon that surrounds the columella. In the Bryidae, the capsules are always lifted up by a seta , which can also be very short. They are never lifted up by a pseudopodium . The young capsules are still enveloped by the tissue of the gametophyte . This eventually tears and falls off, but can also cover the capsule as a kalyptra (hood).

The structure of the peristome is usually family-specific and therefore an important systematic feature.

Large morphological groups

To simplify matters, the Bryidae can be divided into two groups: the acrocarp (summit fruited) and the pleurocarp (side fruited) mosses:

  • In acrocarp deciduous mosses, the archegonia and thus later the sporogons are formed at the tip of the main stem or an equivalent side stem. The stems usually grow upright (orthotropic) and are not very branched.
  • In pleurokarp en Moosen, the archegonia sit on short side branches. The main trunks usually grow prostrate ( plagiotropic ) and are irregular to feathery branched.

However, this division poses many problems. There are prostrate mosses with acrocarpic sporogons, but also upright mosses with pleurocarpic sporogons. The perichaetia (shell formed from leaves around the gametangia stands) are always terminal, i.e. at the end of a (side) shoot. There are two cases, each with two subdivisions:

  1. The Perichaetia are on the main axes.
    1. If the plant stops growing with the formation of the perichaetium, the sporogon is terminal = acrocarp . Most of the short-lived mosses belong here.
    2. A side branch below the perichaetium can continue growth, the plants have a sympodial growth. The sporogon appears to be lateral = pseudopleurocarp . There are both erect and prostrate forms here.
  2. The perichaetium stands on a side branch.
    1. The perichaetia are on reduced, bud-like side branches = pleurocarp . The side branches are always in the armpits of pseudoparaphyllia. Representatives are the Hypnales and Hookeriales .
    2. If the perichaetia are on elongated side branches, this is called cladocarp . This often occurs with crawling main axes ( Climacium , Hypnodendron )

The subdivision does not have a particularly great systematic importance, since several of these forms occur in several genera, such as Fissidens or Racomitrium . However, phylogenetically, pleurocarpy was developed late, the oldest pleurocarp fossil is Muscites gueselinii from the Triassic . The purely pleurocarpic groups of Hypnales, Thuidiaceae, Leucodontaceae and Hookeriales are therefore considered to be young groups that mostly live as ground cover and epiphytes in forests.

Systematics

The Bryidae are a subclass of the Bryopsida within the moss (Bryophyta). In the current description as by Stech and Frey (2009) they form a monophyletic group:

literature

Web links

Commons : Bryidae  - Collection of images, videos, and audio files

Individual evidence

  1. ↑ Wolfgang Frey, Michael Stech, Eberhard Fischer: Bryophytes and Seedless Vascular Plants (= Syllabus of Plant Families. 3). 13th edition. Borntraeger, Berlin et al. 2009, ISBN 978-3-443-01063-8 , pp. 186 ff.