''Atrichum tenellum'', also known as the slender smoothcap, is a species of

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

belonging to the family

Polytrichaceae Polytrichaceae is a common family of mosses. Members of this family tend to be larger than other mosses with a thickened central stem and a rhizome. The leaves have a midrib that bears photosynthetic lamellae on the upper surface. Species in ...

. It is

red list The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

ed in

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

as a critically endangered (CR) species. In Iceland, it is only found in two geothermal areas.Náttúrufræðistofnun Íslands celandic Institute of Natural History(1996).
Válisti 1: Plöntur.
' (in Icelandic) Reykjavík: Náttúrufræðistofnun Íslands.

Description

''A. tenellum'' will form dull brown or green clumps. The species possesses 2cm tall shoots that are erect and unbranched. Leaves are 4.5-5.5mm long and scarcely undulate. The leaves are also narrowly egg-shaped and distinctively narrowed towards the base. They also possess paired marginal teeth down to the mid-leaf.

Habitat

''A. tenellum'' is an uncommon species, which can be found in a range of disturbed,

acidic In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

and open habitats. ''A tenellum'' grows on moist soils such a

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...

or sandy

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

. This species can be found growing in

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

habitats where it inhabits rides, but also in ditches and even open

heathlands A heath () is a shrubland habitat (ecology), habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great B ...

and

grasslands A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natural ...

. Populations can also be found on the banks of streams, lakes and reservoirs where the soil is moist.

References

Polytrichaceae Flora of Iceland Plants described in 1844 {{Bryophyte-stub