Rhizopogon - Rhizopogon luteolus

Scientific classification

Kingdom:        Fungi

Division:          Basidiomycota

Class:   Agaricomycetes

Order: Boletales

Suborder:        Suillineae

Family:            Rhizopogonaceae

Genus: Rhizopogon

Fr. (1817)

Type species   Rhizopogon luteolus

Fr. & Nordholm (1817)

Rhizopogon is a genus of ectomycorrhizal Basidiomycetes in the family Rhizopogonaceae. Species form hypogeous sporocarps commonly referred to as "false truffles".

The general morphological characters of Rhizopogon sporocarps are a simplex or duplex peridium surrounding a loculate gleba that lacks a columnella.

Basidiospores are produced upon basidia that are borne within the fungal hymenium that coats the interior surface of gleba locules. The peridium is often adorned with thick mycelial cords, also known as rhizomorphs, that attach the sporocarp to the surrounding substrate.

The scientific name Rhizopogon is Greek for 'root' (Rhiz-) 'beard' (-pogon) and this name was given in reference to the rhizomorphs found on sporocarps of many species.

Rhizopogon species are primarily found in ectomycorrhizal association with trees in the family Pinaceae and are especially common symbionts of pine, fir, and Douglas fir trees.

Through their ectomycorrhizal relationships Rhizopogon are thought to play an important role in the ecology of coniferous forests. Recent micromorphological and molecular phylogenetic study has established that Rhizopogon is a member of the Boletales, closely related to Suillus.

The genus Rhizopogon occurs throughout the natural and introduced ranges of family Pinaceae trees. Though this range covers much of the northern temperate zones, the diversity of Rhizopogon species is well characterized only in North America and Europe.

There are currently over 150 recognized species of Rhizopogon. The morphology of Rhizopogon species is highly cryptic and characters vary greatly throughout sporocarp maturity. This has led to the description of multiple species from various developmental stages of a single fungus.

The genus Rhizopogon was first described from Europe by Elias Magnus Fries in 1817. The North American monograph was produced by Alexander H. Smith in 1966 with second author credits given posthumously to Sanford Myron Zeller due to his contributions to the study of the genus.

A European monograph of Rhizopogon has also been published. In the recent past, molecular phylogenetic methods have allowed the revision of the taxonomic concepts of the genus Rhizopogon

Modern taxonomic concepts of the genus Rhizopogon recognize five subgenera of Rhizopogon. These are subgenus Rhizopogon, subgenus Versicolores, subgenus Villosuli, subgenus Amylopogon, and subgenus Roseoli.

Rhizopogon species have been established as a common component in the diet of many small mammals as well as deer in Western North America. The viability of Rhizopogon spores is maintained and may even be increased after mammalian gut passage, making mammals an important dispersal vector for Rhizopogon.

Rhizopogon species are common members of the fungal communities that colonize the roots of trees during seedling establishment and persist into old growth stands.

Rhizopogon spores are long lived in soil and the spores of some species can persist for at least four years with an increase in viability over time. Rhizopogon seems to be especially common upon the roots of establishing tree seedlings following disturbance such as fire or logging.

Rhizopogon are also abundant colonizers of pot cultivated and field cultivated conifer seedlings growing in soil from conifer stands that lacked observations of Rhizopogon upon the roots of mature trees.

These finding suggest that Rhizopogon species are an important factor in the recovery of conifer forests following disturbance.

location: Europe

edibility: Inedible

fungus colour: Yellow

normal size: Less than 5cm

cap type: Other

stem type: Lateral, rudimentary or absent

flesh: Flesh discolours when cut, bruised or damaged

spore colour: Olivaceous

habitat: Grows in woods, Grows underground