''Ossicaulis'' is a ditypic genus of

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

s in the family Lyophyllaceae.

Taxonomy

The genus was circumscribed in 1985 to contain the species originally described as ''Agaricus lignatilis'' by Christian Hendrik Persoon in 1801. This was considered the sole species in the genus until 2007, when Marco Contu validly published a description of '' O. lachnopus'' from collections in Italy. Recent analysis (2013) confirms that '' O. lachnopus'' and '' O. lignatilis'' should be considered distinct species. Molecular genetics analysis suggests that ''Ossicaulis'' is most closely related to the genera '' Asterophora'', '' Hypsizygus'', '' Lyophyllum'', and ''

Tricholomella ''Tricholomella'' is a fungal genus in the family Lyophyllaceae. The genus is monotypic, containing the single species ''Tricholomella constricta'', described as new to science by Ukrainian mycologist Mariya Yakovlevna Zerova in 1979. Zerova's ...

''.

Description

''Ossicaulis'' species have gills that are adnexed,

adnate Adnate may refer to: * Adnation, in botany, the fusion of two or more whorls of a flower * Adnate, in mycology, a classification of lamellae (gills) * Conjoined twins Conjoined twins – sometimes popularly referred to as Siamese twins – are ...

or somewhat decurrent and a stipe that is centrally or laterally attached to the cap. The

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

l system is monomitic (meaning only generative hyphae are present), the trama is regular, and there are clamp connections in the hyphae. Spores are small and ellipsoidal in shape. The

cap cuticle The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes th ...

features coral-shaped (coralloid) hyphae, and there are additionally coralloid to narrowly club-shaped cheilocystidia in the

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...

. The two species are similar in most macroscopic characteristics, but they can be reliably differentiated by differences in spore width: ''O. lachnopus'' is 2.8–4.0 by 2.0–2.4

µm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

, while the dimensions of ''O. lignatilis'' spores are 4.0–5.6 by 2.4–3.2 µm.

Habitat and distribution

Both species are widespread throughout Europe; ''O. lignatilis'' is also found in North America. ''O. lachnopus'' tends to grow in natural forested habitats, while ''O. lignatilis'' prefers habitats that are man-made or have been influenced by man, like towns, villages, parks, and avenues. Both species grow on dead and decaying wood of

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

(rarely

coniferous Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant ...

) trees.

References

External links

* {{Taxonbar, from=Q7107467 Lyophyllaceae Agaricales genera