Lesser smoothcap (Atrichum angustatum)

Description

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Lesser smoothcap fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Lesser smoothcap description

Lesser smoothcap is a dull-green moss that forms patches of single, unbranched and upright shoots that have narrow leaves with toothed edges ⁽³⁾. The leaves curl up when the moss becomes dry ⁽³⁾. Mosses are broadly divided into two main types, called 'acrocarpous' and 'pleurocarpous' mosses. This species is an 'acrocarpous' moss ⁽³⁾; these mosses tend to have erect shoots that have limited growth, and terminate in male and/or female sexual structures. Side branches allow further growth to occur ⁽⁴⁾. Close examination allows this species to be distinguished from the other members of the genus Atrichum, as it has smaller spores and cells ⁽³⁾

Size

Height: up to 3 cm ⁽²⁾

Lesser smoothcap biology

Mosses, hornworts and liverworts form a group of plants called bryophytes ⁽³⁾. Bryophytes lack many of the more complex structures of the higher plants, such as a vascular system, and flowers. They do not have roots, instead they have structures called 'rhizoids' which absorb water and anchor the plant to the substrate. All bryophytes have an interesting life cycle consisting of two main parts, called the gametophyte and sporophyte generations ⁽⁴⁾. Plants that are in the gametophyte stage can reproduce sexually. Male organs (antheridia) produce antherozoids which move to the female organs (archgonia). Fertilisation occurs and a 'sporophyte' develops, this structure remains attached to the plant. The sporophyte releases spores which disperse and develop into a new plant ⁽⁴⁾. In the lesser smoothcap, sporophytes are produced very rarely in winter ⁽³⁾.

Lesser smoothcap range

Most UK records of this species are concentrated in the High Weald in Sussex and Kent ⁽⁵⁾, but it has not been seen at a third historic site in this area since 1950 ⁽³⁾. A few scattered records are known from southern Scotland and south Wales ⁽⁵⁾. Outside of the UK this moss has a broad distribution across Europe, reaching as far east as western Asia. It has also been recorded from Iceland, Madeira, the Azores ⁽⁵⁾, Turkey, Japan and eastern and central parts of North America ⁽³⁾.

You can view distribution information for this species at the National Biodiversity Network Gateway.

Lesser smoothcap habitat

Found in woodland rides and paths growing on bare, fairly acidic, damp, shaded, loamy or sandy soil. It has also been recorded from roadside banks, abandoned sandpits and open grassland heaths ⁽³⁾.

Lesser smoothcap status

Classified as Endangered in Great Britain ⁽³⁾.

Lesser smoothcap threats

The threats facing this species are poorly understood, but it is thought that decline in coppicing in woodlands as well as the neglect of woodland rides and paths may be factors ⁽⁵⁾.

Lesser smoothcap conservation

A UK Biodiversity Action Plan Priority Species, the lesser smoothcap has a Species Action Plan which outlines and coordinates proposed conservation measures ⁽⁵⁾. This plan aims to maintain the strong populations of this species ⁽⁵⁾. A survey of the sites is needed to assess the status of this endangered moss ⁽³⁾.

The UK Biodiversity Action Plan for this species is available at UK BAP.

There may be further information about this species available via the National Biodiversity Network Gateway.

Authentication

Information authenticated by Royal Botanic Gardens, Kew:

http://www.rbgkew.org.uk/

Glossary

Acrocarpous

Type of moss, which tend to grow in erect tufts, that display very little or no branching, and have the female sex organs (archegonia) situated at the tips of stems or branches.

Coppicing

Traditional form of woodland management in which trees are cut close to the base of the trunk. Re-growth occurs in the form of many thin poles. Woodlands are cut in this way on rotation, producing a mosaic of different stages of re-growth.

Gametophyte

A life cycle stage in plants, which has one set of chromosomes (threads of DNA protein) in the cell nucleus (a condition known as ‘haploid’), which arises from a spore (which is also haploid). Sex cells (gametes) are produced during the gametophyte stage. This is the dominant life-cycle stage in liverworts and mosses.

Pleurocarpous

Mosses are broadly divided into two main types, called ‘acrocarpous’ and ‘pleurocarpous’ mosses. Pleurocarpous mosses tend to develop as spreading carpets rather than as upright tufts, in which the female sex organs (archegonia) are not situated at the tips of stems or branches, but are produced on short lateral branches.

Rhizoids

Thread-like structures that help to anchor the plant to the substrate, and absorb minerals and water. In liverworts they consist of a single cell, in mosses they are multi-cellular.

Rides

Often the footpaths and access tracks which run through and divide blocks of trees in woodland. Many rides contain a mixture of rich flora and structure, and provide different habitat conditions for a range of wildlife.

Spores

Microscopic particles involved in both dispersal and reproduction. They comprise a single or group of unspecialised cells and do not contain an embryo, as do seeds.

Sporophyte

The stage of a plant life cycle that produces spores (microscopic particles used in dispersal and reproduction). This stage is diploid (in the cell nucleus there are two sets of chromosomes - threads of DNA protein) and is dominant in ‘higher’ plants such as flowering plants.

Vascular system

In plants, the system that allows water and nutrients to move around.

References

1. ITIS, the Integrated Taxonomic Information System (September, 2009)
   http://www.itis.gov
2. Smith, A.J.E. (1996) The moss flora of Britain and Ireland. Cambridge University Press, Cambridge.
3. Church, J.M., Hodgetts, N.G., Preston, C.D. and Stewart, N.F. (2001) British Red Data Books: mosses and liverworts. Joint Nature Conservation Committee, Peterborough.
4. Mosses and Liverworts in Wales (May, 2002)
   http://home.clara.net/adhale/bryos
5. UK BAP (May, 2002)
   http://www.ukbap.org.uk