Eumycetes
Read about Eumycetes in the Standard Cyclopedia of Horticulture
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EUMYCETES A very large and important group of saprophytic or parasitic organisms (fungi) without chlorophyll: thallus (mycelium) composed of fine tubular threads, which are septate: sexual organs usually obscure or apparently wanting: asexual reproduction by spores or by conidia, a modified form of which is termed basidia. The conidia and basidia do not always represent homologous organs. The group is divided into Ascomycetes and Basidiomycetes. The Ascomycetes are characterized by a group of usually 8 spores inclosed in a unicellular sac (ascus), which is produced immediately after the imperfect sexual fertilization. The asci are borne in spherical bodies (perithecia) or in open cups (apothecia). The Perisporiaceae, Discomycetes, Pyrenomycetes, and Tuberaceae are orders within this sub-class. Among the many important economic fungi belonging here are the following: Erysipheae (Downy Mildews); Aspergillus and Penicillium (Fruit Mold, Blue Mold); Morchella (Morel), edible; Nectria (Currant Cane Rust and Tree Canker); Claviceps purpurea (Ergot), parastic in the ovaries of grains; Taphrina (including Exoascus), causing witches' broom, leaf curl of peach, plum pockets, etc.; Saccharomyces (Yeast), causing fermentation in saccharine solutions. The Basidiomycetes are characterized by the production of four spores on a special hyphal tip or thread (basidium). Each spore is raised on a minute slender stalk (sterigma). These spores, in some cases, if not in all, follow immediately after a nuclear fusion, which probably represents a reduced sexual act. In this group are the Ustilagineae (Smuts), infesting the ovaries of grains, etc.; the Uredineae (Rusts), which infest a wide variety of cultivated and wild plants, and among which may be mentioned the wheat rust; the Hymenomycetes (Mushrooms, Toadstools, and Bracket Fungi), which are saprophytic or inhabit timber; and the Gasteromycetes (Puff-balls), which are saprophytic. The rusts exhibit alternation of generations to a most remarkable degree, the different generations often inhabiting different host plants and possessing a wholly different appearance, as well as a wholly different method of spore-formation. Thp Hymenomycetes are saprophytic, except the genus Exobasidium which inhabits the living foliage of various plants, the genus Armillaria which infests living tree-trunks, and many genera of the Polyporaceae (Bracket Fungi) which also attack the wood of living trees. The last-mentioned fungi, including Armillaria, inhabit the trunks and branches of forest trees, causing their death.
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- More information about this class can be found on the division page.
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References
- Standard Cyclopedia of Horticulture, L. H. Bailey, MacMillan Co., 1963
External links
- w:Eumycetes. Some of the material on this page may be from Wikipedia, under the Creative Commons license.
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