Lesser smoothcap  (Atrichum angustatum)

Classified as Endangered in Great Britain (3).

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)

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.

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).

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).

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).

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.