Hymenium

“ It contains an immense number of species, and these are daily being augmented. The general feature in all is the presence of a perithecium, which contains and encloses the hymenium, and at length opening by a pore or ostiolum at the apex. In some the perithecia are simple, in others compound; in some immersed in a stroma, in others free; in some fleshy or waxy, in others carbonaceous, and in others membranaceous. But in all there is this important difference from the Ascomycetes we have already had under consideration, that the hymenium is never exposed. ”

“ Internally is at first a cream-coloured, then greenish, cellular mass, consisting of the sinuated hymenium and young spores, which at length, and when the spores are fully matured become brownish and dusty, the hymenium being broken up into threads, and the spores become free. In earlier stages, and before the hymenium is ruptured, the spores have been found to harmonize with those of Hymenomycetes in their mode of production, since basidia are present surmounted each by four spicules, and each spicule normally surmounted by a spore. ”

“ Again, in some species of fungi, the hymenium, instead of being situated externally, is inclosed in a membrane which bursts when its spores are ripe, and scatters them like a cloud of smoke to the winds. ”

“ Resupinate; margin becoming free and more or less reflexed, usually radiately-toothed, fleshy, tremelloid, tomentose, white; hymenium variously wrinkled and porus, whitish and subtranslucent-looking, becoming tinged with brown in the center. The spores are cylindrical, curved, about 4×1μ. From one to three inches across, remaining pale when growing in dark places. The margin is sometimes tinged with a rose-color, radiating when it is well developed. ”

“ These are Hymenomycetes and Gastromycetes. In Hymenomycetes the hymenium is always exposed in matured plants, as with the common mushroom. When young, some plants are covered with a membrane. In Gastromycetes the hymenium is always concealed within a covering which bursts at maturity, as with the Lycoperdons or puff-balls. Cohort Coniomycetes includes rusts, smuts, etc., formed for the most part on living plants. There is no hymenium present. The spores are produced xxiion the ends of inconspicuous threads, free or enclosed in a bottle-like receptacle called a perithecium. ”

“ The basidial-layer, with stroma, and the hymenium (region of the basidia) , forms the basidio-fructification, which is branched in the Clavariaceæ, and hat-shaped in other Hymenomycetes (in these groups the hymenium is confined to the lower side of the pileus) .
The hymenium of the conidial-layer and basidial-layer is composed entirely of conidiophores, or of conidiophores and sterile hyphæ (paraphyses) which are probably always unicellular. Paraphyses are found in Entomophthora radicans, and in certain Basidiomycetes (e.g. Corticium) .
3. Conidiocarps (pycnidia) . ”

“ A longitudinal slice from the stem will exhibit under the microscope delicate tubular cells, the general direction of which is lengthwise, with lateral branches, the whole interlacing so intimately that it is difficult to trace any individual thread very far in its course. It will be evident that the structure is less compact as it approaches the centre of the stem, which in many species is hollow. The hymenium is the spore-bearing surface, which is exposed or naked, and spread over the gills. ”

“ In such examples as the above we may regard the hymenium (Solenia, Cyphella) , zygospores, or asci as truly invested by later growth, but in the vast majority of cases the processes which result in the enclosure of the spores, asci, &c., in a “fructification” are much more involved, inasmuch as the latter is developed in the interior of hyphal tissues, which are by no means obviously homologous with a stroma. ”

“ Often in thick clusters. Those in the center are frequently distorted by mutual pressure; large, entire, sessile, at first globose; closed at first, then expanding; the margin of the cup more or less incurved, sometimes slightly notched; disk pallid-brown, externally; surface is [Pg 509] covered with a coarsely granular or warty substance which plainly shows in the photograph. The hymenium is generally separable from the substance of the cap. The spores are smooth, transparent, continuous, elliptical, ends obtuse. ”

“ Thallus commonly granulose, and often passing into verrucose and chinky conditions, but scarcely ever areolate, sometimes scant and evanescent; apothecia usually minute or small, and commonly adnate, exciple weak and often becoming covered; hypothecium and hymenium passing from pale through shades of brown, the former becoming darker than the latter, this rarely tinged blue or violet above; spores hyaline, 2-celled. ”

“ The whole plant is gelatinous when fresh, lobed and convolute, often brain-like, and varying in size, according to species, from that of a pin’s head to that of a man’s head. Threads and sporophores are imbedded in the gelatinous substance, [C] so that the fertile threads are in reality not compacted into a true hymenium. With this introduction we may state that the technical characters of the family are thus expressed:—
Hymenium free, mostly naked, or, if enclosed at first, soon exposed; spores naked, mostly quaternate, on distinct spicules = Hymenomycetes. ”

“ The spores are the seeds or reproductive bodies of the mushroom. They are very fine, and invisible to the naked eye except when collected together in great masses. Underneath mushrooms, frequently, the grass or wood will be white or plainly discolored from the spores. The hymenium is the surface or part of the plant which bears the spores. The hymenophore is the part which supports the hymenium. ”

“ Much more complicated are the processes in a large series of “fructifications,” where the mycelium first develops a densely packed mass of hyphae, all alike, in which labyrinths of cavities subsequently form by separation of hyphae in the previously homogeneous mass, and the hymenium covers the walls of these cavities and passages as with a lining layer. ”

“ Fleshy, branched or simple, somewhat round, without a distinct stem. Hymenium continuous, dry, homogeneous. For the most part growing on ground. Fries.
The members of this genus vary greatly in form, which in some is that of a club growing singly or cespitose, while others present a more or less bush-like appearance, being slightly or excessively branched.
The color of the plant covers a wide range, as it may be white, red, yellow, violet or their various shades, and to be in harmony the spores do not confine themselves to one color, but are white, ochraceous or cinnamon. ”

“ Massee, who has given the Puff-Ball group very close study, says that in the gleba of the Lycoperdaceæ, "at a very early period two sets of hyphæ are present. One, thin-walled, colorless, septate and rich in protoplasm, gives origin to the trama, and elements of the hymenium, and usually disappears entirely after the formation of the spores; the second type consists of long thick-walled aseptate or sparsely septate, often colored hyphæ, which are persistent and form the capillitium. The latter are branches of the hyphæ forming the hymenium." ”

“ In the Thelephorei, the lower surface of the cap presents neither gills, pores, nor spines, but instead the hymenium covers an uneven or slightly wrinkled surface, partially striate, sometimes obscurely papillose. The plants of this order assume a great variety of shape, from that of a perfect cup with a central stem to an irregularly and much branched frond. They are generally dry and tough. Very few are recommended as edible. Prof. Peck says of this order that probably no edible species will be found in any of its genera outside of the genus Craterellus. ”

“ A vertical section through an apothecium of Buellia parasema, the thallus below, and a portion of the woody substratum: a, the hymenium, composed of asci and paraphyses; b, the strongly developed, dark colored exciple; c, the dark colored hypothecium; d, the thallus, composed of interwoven hyphae, and enclosing cells of the algal host, a portion of the woody substratum. ”

“ Thallus granulose, passing into chinky, verrucose, subareolate and subsquamulose conditions, seldom or never disappearing; apothecia minute to large, adnate or rarely immersed more or less, exciple usually weak and becoming covered; hypothecium commonly some shade of yellow or brown; hymenium pale to light brown; spores hyaline, acicular, varying from 4- to 16-celled, often curved or variously twisted, usually 8 in each ascus.
KEY TO THE SPECIES OF BACIDIA
1. ”

“ Those which are first formed extend from the edge of the pileus to the stalk; those formed later reach only a longer or shorter portion of this distance, according to their age. In structure the lamellæ (Fig. 174) consist of a central mass of hyphæ, the trama, continuous with the hyphæ of the pileus; these terminate in a layer of shorter cells, the subhymenial layer, immediately beneath the hymenium which is composed of basidia and paraphyses. In a few species, but not in the majority, the lamellæ are branched, and in some they are decurrent. ”

“ The pores at first very large, simple, compound, or confluent, round, elon [Pg 412] gated, flexuous; the dissepiments dentate, then lacerate, the hymenium finally resolved into teeth.
When I first found this plant the hymenium had resolved into teeth, and I supposed that I had found an Irpex. It is found in woods on logs and stumps. Very common with us. Frequently covered with a green lichen. July to November.
Polystictus hirsutus. Fr. [Pg 413] The Bristly Polystictus. ”

“ Only a few solitary instances occur of individual species that are parasitic on living plants.
Fig. 42.—Sphæria aquila.
In the Sphæriacei, the substance of the stroma (when present) and of the perithecia is variable, being between fleshy and waxy in Nectriei, and tough, horny, sometimes brittle, in Hypoxylon. A perithecium, or cell excavated in the stroma which fulfils the functions of a perithecium, is always present. The hymenium lines the inner walls of the perithecium, and forms a gelatinous nucleus, consisting of asci and paraphyses. ”

“ In the family Ascomycetes a minute ascus or spore case envelops the sporidia, and takes the place of the basidium, and the hymenium consists of (1) the asci containing the sporidia, (2) the paraphyses, and (3) a colorless or yellowish mucilage which envelops the paraphyses and asci. The asci are present in all species. In some species, however, the paraphyses are rare, and the mucilaginous substance is entirely wanting. The asci differ in shape and size, according to the species. ”

“ Hymenophore covered with the soft waxy hymenium, which is incompletely porus, or arranged in reticulate, sinuous, dentate folds. This genus grows on wood, at first resupinate, expanded; the hymenophore springing from a mucous mycelium.
Merulius rubellus. Pk. [Pg 424]
Figure 353.—Merulius rubellus. Natural size.
Rubellus is the diminutive of ruber, reddish. The pileus grows in tufts, sessile, confluent and imbricated, repand, thin, convex, soft, dimidiate, quite tenacious; tomentose, evenly red, margin mostly undulately inflexed, growing pale in age. ”

“ Aculei, etc.—The under surface of the pileus in the genus Hydnum is shagged with vegetable spines or teeth (dentes, aculei) of unequal lengths, generally isolated, but sometimes connected at the base, and formed originally out of a congeries of minute papillæ invested by the hymenium, which gradually elongate their fibres and assume this form. Light seems essential to their production, for if a Hydnum grow in the dark, the teeth shrink up into long threads and are sterile. ”

“ The following genera have cartilaginous fruit-bodies.—Calocera (Fig. 162) , with club-like, simple, or branched, Clavaria-like, fruit-bodies; the orange coloured fruit-bodies of C. viscosa grow aggregated together on the wood of Conifers.—Guepinia resembles a Peziza, and has the hymenium only on the hollow upper surface.—Dacryomitra resembles a Mitrula (Fig. 162) .
Family 2. Hymenomycetes.
This family is very rich in species (more than 8000 have been described) , and to it belong all the “Mushrooms” and “Toadstools.” ”

“ These lines are formed by minute microscopic spores that have been thrown down in profusion from the hymenium, and in greatest number from the opposed surfaces of the gills. In making the experiment with this mushroom use white paper, but for light-spored species black paper should be taken. These little germinal bodies are cellular in structure, and of the extremest minuteness; thousands of them are required to form a body the size of a pin's-head. Their color is constant, and is used as a means of identification ”

“ In these forms gonidia are found in connexion with the young fruit; such algal cells undergo numerous divisions becoming very small in size and penetrating into the hymenium among the asci and paraphyses. When the spores are thrown out some of these hymenial gonidia, as they are called, are carried with them. When the spores germinate the germ-tubes surround the algal cells, which now increase in size and become the normal gonidia of the thallus. ”

“ The spores are contained in a capsule or perid ́ium (πηρἱδιον, a little bag) which is often of large size, and are situated upon a hymenium forming folds, partitions (septa) , or a lattice-work.
A small species, Physárum album (Pl. VII. fig. 3) , is often found growing upon rotten stems of plants and decaying sticks. The capsules are minute, grey, brittle, and black within, from the presence of the spores (fig. 4) , which are lens-shaped, and arise from the ends of short filaments. ”