Introduction
Mycorrhizae.
The Apothecium. An apothecium consists of three parts
hymenium- is the layer of asci that lines the surface or hollow part of the disc, cup, saddle, or other variously shaped structures; it is made up of club-shaped or cylindrical asci, usually with paraphyses among them; paraphyses may be as long as the asci, longer, or somewhat shorter. In some apothecia the tips of the paraphyses may be branched, and the tips of the branches united above the asci to form a layer called the epithecium
hypothecium- is a thin layer of interwoven hyphae located immediately below the hymenium.
excipulum- is the apothecium proper (i.e., the fleshy part of the ascocarp that supports the hypothecium and hymenium); the excipulum as consisting of two parts, the ectal excipulum, which is the outer layer of the apothecium, and the medullary excipulum, which is the inner portion.
(IMAGE OF APOTHECIUM)
The Ascus.
The structure of the ascus apex and the method of dehiscence have been used as basic characters in classifying discomycetes.
All these fungi have unitunicate asci and most discomycetes eject their spores forcibly through various types of openings at or near the ascus apex.
In the inoperculate discomycetes, the asci release their spores through an apical, circular perforation or pore.
In the operculate discomycetes, each ascus has at its tip or just below it a hinged cap or lid-like structure, the operculum, which opens and permits the escape of the ascospores.
Less frequently, instead of an operculum, a longitudinal slit opens and releases the spores during discharge from the ascus.
Forcible discharge is lost in the hypogeous discomycetes with closed ascocarps. These discomycetes are the truffles, an artificial group, with asci that evanesce and ascospores that are dispersed by mycophagous animals attracted by odors produced by the ascocarp.
The reaction of the ascal tip to iodine, although not always a consistent character, is also of considerable importance in classifying these fungi.
(IMAGE of Ascus)
Septal pores of some discomycetes have distinctive plugs. These structures may be found at the base of the ascus on the ascus side of the septum. They vary from amorphous material of irregular shape to highly structured dome-shaped structures composed of radiating tubules. Another structure that may be useful at certain levels is the shape of the Woronin body. Although most Woronin bodies are roughly spherical, some are octanginal
(IMAGE of Pores)
Taxonomy and Classification.
Discomycetes traditionally have been divided into groups based on type of ascus dehiscence and ascocarp development and morphology; inoperculate vs operculate
Pezizales
Large order that contains species known as operculate discomycetes as well as derived hypogeous forms that have evanescent asci with ascospores spread by mycophagy.
When the ascus is said to be operculate, it may have an apical operculum or slit at the apex or it may have a slit just below the apex, sometimes called suboperculate
Most Pezizales are saprobic, living on dead wood, soil, or humus; a number of species are ectomycorrhizal.
Sarcoscyphaceae.
Usually have bright colored apothecia, and if melanin pigments are present they are restricted to hairs on the apothecium surface
Most important characters separating this family from others of Pezizales are the multinucleate ascospores and cells of the paraphyses
Ascus possesses a thickened apical ring capped by a plug or hinged operculum, its opening often oriented obliquely a condition that usually is referred to as suboperculate
Asci are long and slender, with a flexuous base
Ascospores are hyaline, variously ornamented, and one-celled.
Majority of the species are tropical fungi; in the temperate zone, one of the earliest and most beautiful species is the scarlet cup fungus Sarcoscypha coccinea, which produces its red apothecia in clusters on buried sticks spores germinate by germ tubes or by the immediate production of conidia
Sarcosomataceae
Several characters in common with Sarcoscyphaceae, such as suboperculate asci and multinucleate ascospores
Lack the bright colors and multinucleate paraphysis cells found in that family.
Urnula craterium is commonly encountered in our northern woods; dark brown or black, deeply cup-shaped, clustered apothecia.
Sarcosoma - heavy gelatinous ascocarps; large brown apothecia of Sarcosoma globosum sometime measure over 7 cm in height and over 5 cm in diameter. The upper portion of the apothecium is hollowed out and bears the hymenium. The basal portion is filled with a jelly that causes the skin-like ectal excipulum to bulge.
Pezizaceae
Apothecia of species placed in Pezizaceae are mostly cup- or disc-shaped may be sessile to stalked; minute to very large; bright-colored to dark-brown; smooth, velvety, hairy, or bristly
Distinguished from Sarcoscyphaceae and Sarcosomataceae by their operculate asci
The ascal apex may be intensly blue or the entire ascus wall difusely blue in iodine
Single-nucleate ascospores are relatively thin-walled
Many of the Pezizaceae grow on the ground or on the dung of animals.
Ascobolaceae
Very thick-walled, uninucleate ascospores.
Asci are operculate and if blueing occurs in the ascus it is diffuse, not intense.
Ascospores usually are hyaline; however, just before discharge those of some species darken
Small sized apothecia
These species are best known from moist chamber culture of dung, and Ascobolus and Saccobolus are common examples of these
Otidiaceae
A heterogeneous group based on the variety of septal pore plugs found within species of the group.
Scutellinia scutellata, whose blood-red apothecia, 2-12 mm in diameter, grow on a variety of substrata, but most often on rotten wood or on bark among mosses. The apothecia are covered externally with dark-brown hairs
Otidea is one of the most interesting cup fungi in the world (Web Author's note)
Pyronemataceae
Family contains species with smooth, nonpigmented ascospores in a reduced ascocarp with only a few cell layers in the exipulum.
Several characters are shared by members of Pyronemataceae and
Ascodesmidiaceae that separate these families from other Pezizales.
(IMAGE)
Pyronemataceae are separated from Ascodesmidiaceae by their smooth hyaline ascospores and exipulum composed of several layers of cells
Pyronema has several species are are well known "fireplace fungi" that are restricted to burned substrates.
Ascodesmidiaceae
Small apothecia which develop from paired ascogonia and antheridia as in Pyronemataceae
Asci are globose to saccate and are formed singly or few in a loose cluster.
Ascodesmidiaceae is distinguished by brown tuberculate, spiney, or reticulate ascospores and almost complete loss of the excipulum
Species of Ascodesmis are coprophilous
Species of Eleutherascus have been isolated from soil and decaying mushrooms; absence of an apothecium in Eleutherascus caused it to be placed in several different taxonomic groups; however, morphology, development, and ultrastructural details support the current placement, although the operculum is not functional
Morchellaceae
Large, stalked apothecia, mostly with a sponge-like or bell-shaped pileus
Ascospores are always multinucleate (20-60 nuclei in each), a character in common with Sarcoscyphaceae and Sarcosomataceae.
The Woronin bodies in members of the family that have been examined are elongated rather than spherical, a character shared with the Hevellaceae includes the morels and the bell morels
Morchella
Apothecia with a thick stalk and a pitted, or sometimes ridged pileus that resembles a sponge
Color varies from a dirty grayish white to a dark-brown
Hymenial layer of a morel lines the pits of the pileus; it consists of long, cylindrical, operculate asci, each containing eight ascospores, and of elongated paraphyses interspersed among the asci.
The ascospores are large, colorless, oval, and, at maturity, multinucleate. subterranean sclerotia
Verpa includes the bell morels
Large apothecia with long, thick, white, somewhat flattened stalks bearing brown, bell-shaped caps that, because of their relatively small size, appear disproportionate to the stalks.
The cap of the ascocarp is attached to the stalk in the center and the margin is free.
The outer surface of the cap that bears the hymenium is either smooth or longitudinally ridged
Like the true morels, bell morels are edible and flavorful. However, it appears that consumption of large quantities of certain species of Verpa temporarily affects muscular coordination of some individuals.
Helvellaceae
Large, stipitate ascocarps varying from cup-shaped to saddle-shaped or variously convoluted
Ascal apex does not blue with iodine, and the invariably quadrinucleate
Ascospores contain conspicuous oil droplets
Woronin bodies are elongated in the family, a character shared with Morchellaceae, so-called saddle fungi and the false morels
Helvella- saddle fungi, with an irregular cap shaped like a saddle, generally borne on a heavily ridged stalk. Helvella lacunosa and compressa are one of the most common saddle fungi in our area. Helvella (Gyromitra) infula usually produces its saddle-shaped, smaller apothecia in the summer and fall.
Gyromitra- so-called false morels
apothecia are quite large and usually much lobed, convoluted, and brain-like rather than saddle-shaped, but no sharp distinction can be drawn between this and the genus Helvella. Gyromitra esculenta in spring. Some people eat saddle fungi and false morels and find them delicious; others each them and die.
Elaphomycetales
Dark thick-walled peridium encloses a single chamber which is lined by ascogenous hyphae that loosely fill it
Evanescent eight-spored asci are globose and lack an apical apparatus. At maturity the yellow brown to black powdery mass of spiney or reticulte ascospores fills the chamber
The order contains on genus,Elaphomyces, the deer fungus
Tuberales
Polyphyletic group
The truffles, some of which epicureans prize highly as food in continental Europe.
The ascocarps are hypogean and remain closed in most species, liberating the ascospores only when the ascocarp decays or is broken by animals.
The asci, in contrast to those of other discomycetes, may be globose or widely oval, and the ascospores are often spherical and spiny .
Geneaceae and the Tuberaceae, the asci form a distinct hymenium
Terfeziaceae they are borne in nest-like areas separated by sterile tissue; this is the main reason the Terfeziaceae were included by some authors in the Elaphomycetales. However, the asci of the latter are evanescent, whereas those of the Terfeziaceae are persistent.
Tuberales are mycorrhizal fungi living in association with the roots of oak and beech trees.