Order 1. Dacryomycetaceæ. This order comprises 4 genera of which the first two develope the hymenium on the whole surface of the fruit-body, but the two last only on its apex.
Dacryomyces: the folded, gelatinous, Tremella-like fruit-bodies break out in winter on dried wood (hedges) in the form of red or yellow drops. D. deliquescens is very common (Fig. [121]). 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.” The fruit-bodies present very various forms; they are generally fleshy, very perishable, seldom leathery or corky, in the last case often perennial. The basidia are more or less cylindrical and bear generally 4 (seldom 2, 6 or 8) sterigmata and basidiospores. The hymenium in the fully-formed fruit-bodies lies free on the surface: in orders 1 and 2 and a portion of order 6 it is from the commencement exposed, fruit-bodies gymnocarpic; orders 3–6 have hemiangiocarpic fruit-bodies (p. [157]). In the first order the basidia (or the hymenium) are developed immediately from the mycelium (Fig. [163]); the fruit-bodies of orders 2 and 3 present a higher grade of development, and have between the mycelium and hymenium a special hyphal-tissue, a stroma, which is crustaceous, club-like, or coralloid, etc., and in general bears the hymenium on the largest part of the free, smooth surface. In the forms most highly developed (orders 4–6) a new tissue—the hymenophore—is introduced between the stroma and hymenium, which appears on the under side of the fruit-body in the form of warts, projections, tubes, folds or lamellæ (Figs. [166], [167], [174] bc). Paraphyses are frequently found in the hymenium, among the basidia. In the Hymenomycetes few examples of conidia can be recognised at first. More frequently chlamydospores are found, particularly oidia. The mycelium is richly branched, generally colourless, often perennial; it lives in humus or decaying wood, and is seldom parasitic. The hyphæ generally have clamp-connections and unite, sometimes, to form a rhizomorpha (Fig. [177]) or sclerotia with coloured, pseudo-parenchymatous covering.
Fig. 163.—Exobasidium vaccinii. I Hypertrophied stem of Vaccinium vitis idæa; II leaf with gall-like swelling; III section of II; IV transverse section: m mycelium between the parenchymatous cells; p hypodermal cells; e epidermis with basidia in various stages of development; V epidermis with germinating spores; VI and VII spores germinating in water (IV-VII × 620).
Order 1. Tomentellaceæ. To this order belong the simplest of the Hymenomycetes. The basidia (Fig. [145]) arise free and irregularly from the mycelium; a hymenium is entirely absent or very slightly formed (in Corticium it attains its highest development); fruit-bodies are also wanting.—In general they form flaky, membranous or leathery coverings on bark and wood. Some are parasites.
Hypochnus without conidia.—Tomentella with conidiophores; growing on wood or earth.—Exobasidium vaccinii (Fig. [163]), a parasite on Vaccinium, Andromeda, Arctostaphylos, and Rhododendron, forms flaky-powdery, white or red coverings and may cause hypertrophy of the parts attacked. E. warmingii is parasitic on Saxifraga; E. lauri causes outgrowths on the stem of Laurus canariensis as long as a finger, which formerly were regarded as aerial roots.—Corticium forms membranous to leathery layers or crusts; C. quercinum on wood and bark, particularly Oak, is flesh-coloured; C. cæruleum has a blue hymenium; C. giganteum on the bark of fallen Pine-trees.
Order 2. Clavariaceæ. The hymenium is situated on a stroma, and either completely covers the smooth surface of the more or less fleshy gymnocarpic fruit-body, or is confined to a tolerably well defined upper portion of it (Typhula). Paraphyses absent. The vertical, white, yellow, or red fruit-bodies are roundish or club-like, undivided or richly branched (Fig. [125]). Generally on the ground in woods, seldom on tree-stems, etc.
