真藓纲纲

分类

本纲可分为三个亚纲：泥炭藓亚纲仅有一目一科，泥炭藓目（Sphagnales），泥炭藓科（Sphagnaceae），泥炭藓属（Sphagnum），约300余种，多分布于北半球温带地区。中国的主要分布于东北、西北和西南高寒沼泽地区，常见的有泥炭藓。

黑藓亚纲仅有一目一科，黑藓目（Andreaeales），黑藓科（Andreaeaceae），两个属，中国仅有黑藓属（Andreaea），疣黑藓分布于陕西、安徽和福建。

真藓亚纲最大，有12—19目，真藓目（Bryales），是苔藓植物中科、属、种最多的一个目，遍布全世界。中国常见的有葫芦藓。

泥炭藓亚纲 Sphagnopsida

泥炭藓目 Sphagnales

黑藓亚纲 Andreaeopsida

黑藓目 Andreaeales

真藓亚纲 Bryopsida

无轴藓目 Archidiales

无轴藓科 Archidiaceae

无轴藓属 Archidium Brid.

• 真藓目 Bryales
• 曲尾藓目 Dicranales
• 凤尾藓目 Fissidentaceae
• 葫芦藓目 Funariales
• 紫萼藓目 Grimmiales
• 旋叶藓目 Helicophyllales Stech & Frey, 2008
• 旋叶藓科 Helicophyllaceae

旋叶藓属 Helicophyllum Brid.

Helicophyllum torquatum (Hook.) Brid.

• 油藓目 Hookeriales
• 灰藓目 Hypnales
• 变齿藓目 Isobryales
• 木灵藓目 Orthotrichales
• 丛藓目 Pottiales
• 光藓目
• 羽藓目

The Bryopsida constitute the largest class of mosses, containing 95% of all moss species. It consists of approximately 11,500 species, common throughout the whole world.

The group is distinguished by having spore capsules with teeth that are arthrodontous; the teeth are separate from each other and jointed at the base where they attach to the opening of the capsule. Consequently, mosses in the Class Bryopsida are commonly known as the "joint-toothed" or "arthrodontous" mosses. These teeth are exposed when the covering operculum falls off. In other groups of mosses, the capsule is either nematodontous with an attached operculum, or else splits open without operculum or teeth.

Morphological groups

The Bryopsida can be simplified into three groups: the acrocarpous (pinnate), the pleurocarpous (side-fruited), and the cladocarpous (branching) mosses. This is based on the position of the perichaetia and sporophytes.

Acrocarps are generally characterized by an upright growth habit that is unbranched or only sparingly branched. Branching is usually sympodial with the branches similar to main shoot where they originate. Branches below the perichaetium are called subfloral innovations.

Pleurocarps are generally characterized by creeping shoot systems and extensive lateral branching. The main stem is indeterminant and offshooting branches may be dissimilar. The perichaetia in pleurocarps are produced at the tips of extremely reduced, basally swollen lateral branches that are morphologically distinct from the vegetative branches.

Cladocarps are mosses which produce perichaetia at the tips of unspecialized lateral branches. Such branches are themselves capable of branching.

Although acrocarps, pleurocarps, and cladocarps generally have different branching habits, it is the morphology of the perichaetia which defines the groups.

Capsule structure

Among the Bryopsida, the structure of the capsule (sporangium) and its pattern of development is very useful both for classifying and for identifying moss families. Most Bryopsida produce a capsule with a lid (the operculum) which falls off when the spores inside are mature and thus ready to be dispersed. The opening thus revealed is called the stoma (meaning "mouth") and is surrounded by one or two peristomes. A peristome is a ring of triangular "teeth" formed from the remnants of specially thickened cell walls. There are usually 16 such teeth in a single peristome, and in the Bryopsida the teeth are separate from each other and able to both fold in to cover the stoma as well as fold back to open the stoma. This articulation of the teeth is termed arthrodontous.

There are two basic arthrodontous peristome types. The first type is termed haplolepidous and consists of a single circle of 16 peristome teeth. This type of peristome is characteristic of subclass Dicranidae. The second type is the diplolepidous peristome found in subclasses Bryidae, Funariidae, and Timmiidae. In this type, there are two rings of peristome teeth—an inner endostome (short for endoperistome) and an exostome. The endostome is a more delicate membrane, and its teeth are aligned between the teeth of the exostome. There are a few mosses in the Bryopsida that have no peristome in their capsules. These mosses still undergo the same cell division patterns in capsule development, but the teeth do not fully develop.

Classification

In the past, the group Bryopsida included all mosses. Current circumscriptions of the group are more limited.

Phylogeny

A detailed phylogeny to the level of order, based on the work by Novíkov & Barabaš-Krasni 2015; Cole, Hilger & Goffinet 2021; Fedosov et al. 2016; Ignatov, Fedosov & Fedorova 2016; Bechteler et al. 2023.

Unassigned Dicranidae:

Pseudoditrichales