Haplomitrium
| Haplomitrium | ||||||||||||
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Haplomitrium hookeri |
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| Systematics | ||||||||||||
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| Scientific name of the class | ||||||||||||
| Haplomitriopsida | ||||||||||||
| Stotler & Crand.-Stotl. | ||||||||||||
| Scientific name of the order | ||||||||||||
| Haplomitriales | ||||||||||||
| H. Buch ex Schljakov | ||||||||||||
| Scientific name of the family | ||||||||||||
| Haplomitriaceae | ||||||||||||
| Dědeček | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Haplomitrium | ||||||||||||
| Nees |
Haplomitrium is a systematically very isolated genus of mosswithin the liverwort . Today the genus Calobryum is also counted to it, which is why the ordinal name Calobryales is replaced by Haplomitriales.
features
The stems grow upright and branched. They have no rhizoids , but chlorophyll-free, rhizome- like structures whose outer cells are infected with fungal symbionts. The foliage of the stems is three lines.
Many features are unique among mosses:
- The absence of rhizoids
- The single-layer capsule wall has special cell wall thickenings.
- The spermatozoids have an accessory row of microtubules and thus resemble those of the ferns .
- The genus has no plastid tubules and is similar to green algae .
- She has no specialized androezia and gynecia. The antheridia and archegonia are instead bare in the leaflet axils.
Systematics
The structure of the sporogon and the presence of elaters are the reasons why the genus is assigned to the liverworts. However, several characteristics separate the genus from the other liverworts:
- They have a central cord like only some Pallaviciniaceae in liverworts .
- They have an underground rhizome.
- The gametangia develop differently.
- The protonema is filamentous.
- The Seta is massive.
- The archegonium has a long stalk.
- A kalyptra is formed.
- The leaves are similar ( isophyll ) and three rows.
- The sheets advertise across.
Frahm and Frey (2004) place the genus Haplomitriopsida in its own class. The genus consists of eight species worldwide, of which only Haplomitrium hookeri (Sm.) Nees occurs in Central Europe .
literature
- Jan-Peter Frahm, Wolfgang Frey, J. Döring: Moosflora . 4th, revised and expanded edition (UTB for Science, Volume 1250). Ulmer, Stuttgart 2004, ISBN 3-8001-2772-5 (Ulmer) & ISBN 3-8252-1250-5 (UTB)
- Jan-Peter Frahm: Biology of Mosses . Spectrum Academic Publishing House, Heidelberg and Berlin 2001, ISBN 3-8274-0164-X