Fig. 158.—Æcidium strobilinum: a scale of cone of Picea excelsa, with numerous æcidia; b æcidiospores arranged in a series; c a cell of the peridium.
Order 2. Auriculariaceæ. The long, transversely divided basidia bear laterally 4 long sterigmata with basidiospores (Fig. [160] B) and are united to form an hymenium on the surface of the fruit-body. Parasites or saprophytes.
Auricularia sambucina (Auricula judæ), Judas’-ear, has large fruit-bodies, which may attain the size of several inches, resembling an ear or a mussel shell. In the moist condition they are flesh-coloured, tough and gelatinous, but when dried, become hard, grey and wrinkled; the exterior is covered with short hairs; while the internal surface bears the hymenium. Habitat: stems and branches of old Elder-trees (Sambucus).
Order 3. Tremellaceæ. The round, pear-shaped, longitudinally divided basidia bear 4 elongated sterigmata, situated apically, and 4 basidiospores (Fig. [160] C, D), and are united into the hymenium on the surface of the fruit-body. The fruit-bodies are frequently gelatinous and quivering; similar fruit-bodies are also found in the Dacryomycetaceæ and Hydnaceæ. Simple conidiophores, which appear not infrequently in the basidiocarps, before the basidia, are known in many species. Saprophytes.
Fig. 159.—Peridermium strobi: æcidia of Cronartium ribicola (nat. size).
Fig. 160.—B Auricularia sambucina: a-d basidia in various stages of development; e a sterigma bearing a spore.—C Tremella lutescens: a-d basidia seen from various sides (b from above) and in various stages of development; e sterigma with basidiospore (× 400). D Exidia glandulosa: a-c various stages in the development of a basidium; d sterigma with basidiospore (× 350).
Exidia has kidney-shaped, oblong basidiospores, and small, hook-like conidia; E. glandulosa, E. albida, etc., on wood.—Craterocolla has conidiocarps; C. cerasi on Cherry-wood.—Sebacina incrustans; the yellow, fleshy, or cartilaginous fruit-bodies are found in autumn covering the ground in moist woods.—Tremella has round basidiospores; T. mesenterica has irregularly-folded, quivering, orange fruit-bodies, about one inch in breadth; T. lutescens (Fig. [161]) has orange-yellow conidial-and yellow basidial-layers; T. frondosa has fruit-bodies upwards of a foot in breadth.