The Hydnaceae are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

in the order

Cantharellales The Cantharellales are an order of fungi in the class Agaricomycetes. The order includes not only the chanterelles (Cantharellaceae), but also some of the tooth fungi (Hydnaceae), clavarioid fungi ( Aphelariaceae and Clavulinaceae), and cortici ...

. Originally the family encompassed all

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of fungi that produced

basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp (fungi), sporocarp of a basidiomycota, basidiomycete, the Multicellular organism, multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are chara ...

(fruit bodies) having a

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 ...

(

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

-bearing surface) consisting of slender, downward-hanging tapering extensions referred to as "spines" or "teeth", whether they were related or not. This artificial but often useful grouping is now more generally called the hydnoid or tooth fungi. In the strict, modern sense, the Hydnaceae are limited to the

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 ...

Hydnum ''Hydnum'' is a genus of fungi in the family Hydnaceae. They are notable for their unusual spore-bearing structures of teeth rather than gills. The best known are the edible species ''Hydnum repandum'' and '' H. rufescens''. There are no known t ...

'' and related genera, with basidiocarps having a toothed or poroid hymenium. Species in the family are

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 ...

, forming a mutually beneficial relationship with the roots of trees and other plants. ''

Hydnum repandum ''Hydnum repandum'', commonly known as the sweet tooth, wood hedgehog or hedgehog mushroom, is a basidiomycete fungus of the family Hydnaceae. First described by Carl Linnaeus in 1753, it is the type species of the genus '' Hydnum''. The fun ...

'' (the hedgehog fungus) is an

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from "eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

species, commercially collected in some countries and often marketed under the French name ''pied de mouton''.

Taxonomy

History

The family was originally described in 1826 by French botanist François Fulgis Chevallier to accommodate all the larger fungi with a toothed or spiny

. As such, the family was entirely artificial, bringing together a diverse assemblage of species that have subsequently been reassigned to various families. In 1933, Dutch

mycologist Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...

Marinus Anton Donk Marinus Anton Donk (14 August 1908 – 2 September 1972) was a Dutch mycologist. He specialized in the taxonomy and nomenclature of mushrooms. Rolf Singer wrote in his obituary that he was "one of the most outstanding figures of contemporary myc ...

radically limited the Hydnaceae (which he referred to the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...

Hydneae) to ''

'' and related species that produced "stichic"

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 ...

(basidia with nuclear spindles arranged longitudinally). He considered this feature placed these species closer to the chanterelles (

Cantharellaceae The Cantharellaceae are a family of fungi in the order Cantharellales. The family contains the chanterelles and related species, a group of fungi that superficially resemble agarics (gilled mushrooms) but have smooth, wrinkled, or gill-like hyme ...

) than to other hydnoid fungi. Donk's disposition of the family was widely accepted and a standard 1995 text placed ''Hydnum'' and the Hydnaceae within the

, though still retaining some additional genera ('' Amylodontia'', ''

Climacodon ''Climacodon'' is a widespread genus of tooth fungi in the family Phanerochaetaceae. Taxonomy The genus was circumscribed by Finnish mycologist Petter Karsten in 1881 with ''Climacodon septentrionalis'' as the type species. This fungus was orig ...

'', ''

Corallofungus ''Corallofungus'' is a genus of fungi in the Hydnaceae family. The genus is monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not in ...

'', '' Dentinum'', ''

Gloeomucro ''Gloeomucro'' is a genus of fungi in the Hydnaceae The Hydnaceae are a family of fungi in the order Cantharellales. Originally the family encompassed all species of fungi that produced basidiocarps (fruit bodies) having a hymenium (spore-bear ...

'', '' Nigrohydnum'', '' Phaeoradulum'', and '' Stegiacantha'') within the family. Most of these have now been placed elsewhere.

Current status

Molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

research, based on

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis of

DNA sequences A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usua ...

, has confirmed Donk's placement of the Hydnaceae as a family within the Cantharellales. The precise boundaries of the family have not been investigated, but it appears that the type and related species of the genus ''

Sistotrema ''Sistotrema'' is a genus of fungi in the family Hydnaceae. The genus contains at least 55 species and has a worldwide distribution. The type species is ''Sistotrema confluens'' Pers. (1794). Ecology The genus includes both terricolous and l ...

'' belong within the Hydnaceae, as well as most species of ''Hydnum'' itself. These ''Sistotrema'' species have poroid basidiocarps and are not closely related to the majority of "''Sistotrema''" species which may belong within the

Clavulinaceae The Clavulinaceae are a family of fungi in the order Cantharellales. The family is not well defined, but currently comprises species of clavarioid (club and coral) fungi as well as some corticioid (crust- and patch-forming) fungi. These specie ...

. The status of ''Corallofungus'' has not been investigated. According to the ''Dictionary of the Fungi'' (10th edition, 2008), the family contains 9 genera and 190 species. The placement of the Hydnaceae as a family within the Cantharellales:

Phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

presenting the current opinion on relationships among genera:

Description

The

fruit bodies The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...

of species in the family have

caps Caps are flat headgear. Caps or CAPS may also refer to: Science and technology Computing * CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters * Composite Application Platform Suite, by Java Caps, a Java ...

and stems that are usually centrally attached. Colors typically range from white to yellow to orange, and the teeth are typically lighter than the cap surface. The

flesh Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscle Skeletal muscles (commonly referred to as mu ...

is fleshy and brittle, and monomitic (consisting of generative

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 ...

e only). The generative hyphae are thin-walled, branched, contain

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

, and have

clamp connection A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of Basidiomycetes fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rece ...

Spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

s range in shape from roughly spherical to egg-shaped, have a smooth surface, and are colorless. A distinctive characteristic of many species in the family is the structure of the

(spore-bearing surface), which consists of pendant, toothlike spines.

Habitat and distribution

All species within the Hydnaceae are believed to be

, forming a mutually beneficial relationships with the roots of living trees and other plants. Basidiocarps typically occur on the ground or in

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

in woodland. The family has a

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

Economic importance

Several species of ''Hydnum'' are

and ''Hydnum repandum'' is commercially collected and marketed in Europe, often under the French name ''pied de mouton''. In North America, the related ''

Hydnum umbilicatum ''Hydnum umbilicatum'', commonly known as the depressed hedgehog, is a species of tooth fungus in the family Hydnaceae. It was scientifically described in 1902 by American mycologist Charles Horton Peck. It is found in North America and in Eur ...

'' is also commercially collected, sometimes under the name "sweet tooth".

References

{{Taxonbar, from=Q2466809 Cantharellales Basidiomycota families