Metzgeriidae

Metzgeriidae
	Aneura pinguis
Systematics
without rank:	Phragmoplastophyta
without rank:	Streptophyta
Empire :	Plants (Plantae)
Department :	Liverworts (Marchantiophyta)
Class :	Jungermanniopsida
Subclass :	Metzgeriidae
Scientific name
	Metzgeriidae
	Barthol.-Began

The Metzgeriidae are a subclass of liverworts and include simple thallose mosses.

features

The representatives are always void, and sheet-like attachments never appear. The thales can be large, fleshy and undifferentiated (as in Verdoornia and Aneura ) or small, delicate and differentiated in midrib and wings (as in Metzgeria ). The Metzgeriaceae family lacks oil bodies ; the others have one or more large or small oil bodies per cell. The rhizoids sit on the midrib, but there are also rhizoids along the edge of the thallus.

Antheridia and archegonia each stand in groups in sharply defined groups on special thallus branches. The antheridia are short stalked. The archegonies are often reduced and few in number.

The sporophytes are embedded in a fleshy tissue called calyptra or perigynium. There are no other protective devices. The capsule has four flaps or opens with a slit on the side. The elaters are simply twisted or not twisted, and rather short. The spores are often less than 20 micrometers in size.

The connection between gametophyte and sporophyte is formed as follows: the placenta cells lack invaginations of the cell wall on both sides. In the space there are collapsed cells that come from the gametophyte. This lack of transfer cells in the gametophyte generation is interpreted as a reduction.

Asexual reproduction is common.

The most common chromosome number is n = 9, but there are also n = 8, 10, 18 and 20.

Systematics

The subclass was established by Bartholomew-Began in 1990 for the simple thaleless liverworts ("Jungermanniales anacrogynae"). The Metzgeriidae probably represent a rather young evolutionary line of secondary thaleless liverworts. In the systematics presented here, they include two orders with eleven genera and around 330 species.

The Metzgeriidae are subdivided as follows.

Order aneurals
- Family Aneuraceae
- Mizutaniaceae family

Order Metzgeriales

Metzgeriaceae family

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h 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. 109 ff .

[Syllabus-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h 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. 109 ff .