Swimming liver moss

Swimming liver moss
Swimming liver moss ( Ricciocarpos natans )
Systematics
Class : Marchantiopsida Subclass : Marchantiidae Order : Ricciales Family : Ricciaceae Genre : Ricciocarpos Type : Swimming liver moss
Scientific name of the  genus
Ricciocarpos
Corda
Scientific name of the  species
Ricciocarpos natans
( L. ) Corda

Half rosette, fan-shaped thalli; these break apart easily, creating the typical heart shape (see below)

Close up of swim shape; The ribbon-like abdominal scales under water are clearly visible here

In terms of aspect, the floating carpet by Ricciocarpos looks relaxed

Landform on the limous mud floor of a partially dried-out pond

More fully rosette landforms (taken six weeks later in the same biotope as the previous picture)

Single thallus between numerous small duckweed

Some floating liver moss hidden between large algae fern ( Azolla filiculoides )

The swimming liver moss ( Ricciocarpos natans , syn .: Ricciocarpus natans ), also known as swimming liverwort and ( swimming ) water star liver moss , is a liverwort that floats on bodies of water and is distributed worldwide. The species, which forms its own ( monotypical ) genus, occurs regionally only rarely and unsteadily. It is also non-specialists Moos at least in the aquatilen easily recognizable shape and hardly with other floating aquatic plants like duckweed , algae ferns or Riccia- confuse species. The swimming liver moss is displaced by water pollution and eutrophication .

features

The one- or two-house occurring species consists of a fan-shaped or heart-shaped (= quarter to half rosette), two to three times divided thallus , which is four to nine millimeters wide and ten millimeters long. On the top it is colored green and fielded. At the edge and underneath the color is brown to purple. In the swimming form, there are long, ribbon-shaped abdominal scales with serrated edges that hang down into the water. In addition, plenty of smooth-walled rhizoids (root felt) are formed on the underside. The base fabric is equipped with oil body cells and polygonal air chambers. The respiratory openings are surrounded by five to six delicate-walled border cells. Gametangia (containers of the reproductive organs) sit sunk in the middle furrow of the thallus. Generative reproduction, however - at least in Europe - apparently only plays a subordinate role; Sporogons are only very rarely trained here. In America, on the other hand, monoecious specimens that regularly fruit are said to dominate.

An essential survival and spreading strategy is the vegetative division by breaking up the thalli into smaller sections. These are transported to other bodies of water through attachment to water birds ( epichory ). In autumn they sink to the bottom of the water, only to rise to the surface in the following spring. In this phase the floating thallus sections are often very small and therefore difficult to distinguish from duckweed on a cursory glance. In the course of temporary dehydration of the water, a landform with a different appearance can arise; it grows in two to three centimeters spread (full) rosettes of light green thalli and with strongly shortened ventral scales. The terrestrial form can theoretically be confused with certain star liver mosses of the genus Riccia - for example Riccia glauca - which, however, have different habitat requirements.

Distribution and location requirements

The swimming liver moss is cosmopolitan, especially in the warm areas of the temperate zones; in the northern hemisphere the area extends up to the 62nd degree of latitude, in the southern hemisphere up to 45 °. In Europe, there are deposits from southern Finland and central Sweden in the north to northern Italy and the Caucasus in the south. To the west-east, the area extends from the British Isles to Moscow. However, the moss is often only scattered and sometimes inconsistent. In Germany, for example, river valleys and river valleys in the lowlands are populated selectively, mountain regions only rarely.

The species prefers meso- to eutrophic (moderately nutrient-rich), low- phosphate , weakly nitrate - but ammonium-containing standing water in (semi) sunny to shady, sheltered locations; This can, for example, near-shore sections of ponds, ditches, quiet lake bays and warm summer backwaters be, but also Schlenken in alder swamps and lowland forests . In terms of plant sociology, swimming liver moss forms its own, species-poor association, the so-called Ricciocarpetum natantis, and is often associated with duckweed plants such as the three-furrowed duckweed or with its close relative, the flooding pond liver moss . If duckweed outgrowth, for example as a result of increased phosphate concentration or increased exposure to the sun, the species is pushed back. She finds retreats in Großseggenrieden , between reed stalks or under bushes on the banks. A carpet of swimming liver moss is typically characterized by a loosened aspect, as the abdominal scales spread under water ensure a certain distance between the thalli. In this way, more light can penetrate into the water than, for example, in stocks of densely attached shoots of duckweed.

Swimming liver moss is adapted to the fact that the water or its bank zone can periodically dry out. The plant then forms a landform on the exposed mud or clay soil. To do this, the abdominal scales are first reduced and the rhizoids anchor in the moistened substrate. In prolonged dry phases, fully rosette and correspondingly much wider thalli can develop.

Danger

The species reacts sensitively to water eutrophication or the infiltration of herbicides and is also weak competitive against eutraphent plants such as duckweed. In Central Europe, among others, the swimming liver moss is now a rather rare and threatened species after significant declines.

Red list status (selection)

• Federal Republic of Germany: 3 - endangered
  • Baden-Württemberg: 3 - endangered
  • Berlin: 0 - extinct or lost
  • Brandenburg: 3 - endangered
  • Mecklenburg-Western Pomerania: safe
  • Lower Saxony / Bremen: 3 - endangered
  • North Rhine-Westphalia: 2 - highly endangered
  • Saxony: V - warning list
  • Saxony-Anhalt: 3 - endangered
  • Schleswig-Holstein: 2 - endangered
• Austria: 2 - endangered
• Switzerland: VU - endangered / vulnerable (also "protected species" according to NHV, Appendix 2)

swell

literature

• Jan-Peter Frahm, Wolfgang Frey: Moosflora. 4th edition. UTB 1250, Ulmer, Stuttgart 2004, p. 52. ISBN 3-8252-1250-5 .
• Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 , p. 405.
• Heinz-Dieter Krausch : Color atlas of water and bank plants. Ulmer, Stuttgart 1996, p. 174. ISBN 3-8001-3352-0 .
• Richard Pott: The plant communities in Germany. Ulmer, Stuttgart 1992, p. 42. ISBN 3-8252-8067-5 .
• Michael Sauer (arr.): Ricciaceae, star liver moss. In: Martin Nebel, Georg Philippi (Hrsg.): Die Moose Baden-Württembergs. Volume 3: Special Part (Bryophyta: Sphagnopsida, Marchantiophyta, Anthocerotophyta). Ulmer, Stuttgart 2005, p. 114 ff. ISBN 3-8001-3278-8 .

Individual evidence

1. ↑ Website of the Essex Botany and Mycology Groups ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
2. ^ G. Ludwig, R. Düll, G. Philippi, M. Ahrens, S. Caspari, M. Koperski, S. Lütt, F. Schulz & G. Schwab: Red List of Mosses (Anthocerophyta et Bryophyta) Germany. Publication series Vegetationskunde 28 (1996): 189–306. Table. Synopsis of the endangered plants in Germany. (PDF).
3. ↑ Heike Hofmann, Niklaus Müller, Norbert Schnyder: Information sheets on species protection - Mosses. 2006. ( PDF download address )
4. ^ LUBW (Ed.): Red List and Species Directory of Mosses in Baden-Württemberg. 2005. (PDF).
5. ↑ Jürgen Klawitter: Red list and total species list of mosses (Bryophyta) from Berlin. Processing status: September 2004. ( Memento of the original dated February 23, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF). 
6. ↑ MUGV (Ed.): Rote Liste Moose.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF) In: Nature Conservation and Landscape Management in Brandenburg. 11 (4), 2002.  
7. ^ Christian Berg, Christoph Linke, Wolfgang Wiehle: Red List of Mosses (Bryophyta) Mecklenburg-Western Pomerania. Status: November 2009 (PDF).
8. ↑ Monika Koperski: Red list and list of total species of mosses in Lower Saxony and Bremen. 3rd version, as of 2011. Information Service for Nature Conservation Lower Saxony 31 (2011), No. 3: pp. 131–205.
9. ↑ Carsten Schmidt et al .: Red list and species directory of the liverwort and hornwort, Hepaticophyta et Anthocerophyta, in North Rhine-Westphalia. 3rd version, as of August 2011. (PDF).
10. ^ Frank Müller: Red List Moose Saxony. 2007.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF).  
11. ↑ Ludwig opinion, Peter Schütze: Red list of mosses of the state of Saxony-Anhalt. 2nd version, as of January 2004 (PDF).
12. ↑ Florian Schulz: The Moose Schleswig-Holstein - Red List. 2002. (PDF).
13. ↑ J. Saukel, H. Köckinger: Red list of endangered liverworts (Musci) and hornworts (Anthocerotae) Austria. 2nd version. In: H. Niklfeld (Ed.): Red List of Endangered Plants Austria. 2nd, revised edition (1999): pp. 172–179.
14. ^ National inventory of the Swiss moss flora, Institute for Systematic Botany of the University of Zurich: Checklist of the Swiss mosses. ( PDF online )

Web links

Commons : Ricciocarpos natans  - collection of images, videos and audio files

• Distribution map for Germany and information at moose-deutschland.de
• Pictures and information about Ricciocarpos natans at dr-ralf-wagner.de