''Rhizopogon'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
ectomycorrhizal
An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobi ...
basidiomycetes
Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...
in the family
Rhizopogonaceae
''Rhizopogonaceae'' are a family of fungi in the order Boletales. The family, first named and described by botanists Ernst Albert Gäumann and Carroll William Dodge in 1928, contains 2 genera and 151 species. The genus ''Fevansia'', formerly tho ...
. Species form
hypogeous sporocarps commonly referred to as "
false truffle
A false truffle or a hymenogastrale is any species of fungus that has underground fruiting bodies that produce basidiocarps resembling the true truffles of genus ''Tuber
Tubers are a type of enlarged structure used as storage organs for nutri ...
s". The general
morphological characters of ''Rhizopogon'' sporocarps are a
simplex
In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. The simplex is so-named because it represents the simplest possible polytope in any given dimension. ...
or
duplex peridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi.
Description
Depending on the species, the peridium may vary from being paper-thin to thick and rubber ...
surrounding a
loculate gleba
Gleba (, from Latin ''glaeba, glēba'', "lump") is the fleshy spore-bearing inner mass of certain fungi such as the puffball or stinkhorn.
The gleba is a solid mass of spores, generated within an enclosed area within the sporocarp. The continu ...
that lacks a
columnella.
Basidiospores
A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pro ...
are produced upon
basidia
A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...
that are borne within the fungal
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 ...
that coats the interior surface of gleba locules. The peridium is often adorned with thick mycelial cords, also known as
rhizomorph
Mycelial cords are linear aggregations of parallel-oriented hyphae. The mature cords are composed of wide, empty vessel hyphae surrounded by narrower sheathing hyphae. Cords may look similar to plant roots, and also frequently have similar functio ...
s, 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
The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, larches, pines and spruces. The family is included in the order Pinales, ...
and are especially common
symbionts of
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...
,
fir, and
Douglas fir
The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...
trees. Through their ectomycorrhizal relationships ''Rhizopogon'' are thought to play an important role in the ecology of
coniferous forests
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 exta ...
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