A Mycorhiza from the Lower Coal-Mėasures

Abstract

With Plates XVHI and XIX and a Figure in the Text LL who have investigated the microscopic structure of fossil plants \ are familiar with traces of fungal hyphae and occasional fungal sporangia in and around the plant-remains. An excellent critical account of our knowledge of such fossil Fungi will be found in Seward's ' Manual of Fossil Plants' ('98), in which he has not only recorded the Fungi described by Williamson, Renault, Conwentz, and other observers, but discusses their possible systematic position. In • summing' up our knowledge of this group of plants, he remarks that 'we have fairly good and conclusive evidence of the existence in Permo-Carboniferous times of Phycomycetous Fungi.' Judging from the appearance of the tissues in which these Fungi are found, one is led to the conclusion that they were for the greater part of a saprophytic nature. This would seem more particularly so in the case of the fossil plants from the English Coal-Measures, the internal structure of which is so fully known from the remains found in the nodular concretions, the so-called 'coal-balls' of the Bullion Coal. In these coal-balls, which, according to Lomax ('02), were probably not formed in situ, the plantremains are often of a very fragmentary character, and show traces of having undergone considerable decomposition. The tissues are often penetrated by Stigmarian rootlets, and show signs of having been bored by wood-eating animals. They also show not infrequently internal mycelia, while apparent fungal sporangia are found both within the fossil plants and in the debris lying between them. Indeed, the conditions under which these nodules were formed would seem to have been most favourable for the growth of saprophytic Fungi. Some of the fossil Fungi, however, from the silicified nodules at Grand Croix which have been described by Renault ('83) and Bertrand f 85), and more recently by Oliver ('03), seem to have been of a parasitic nature and to have belonged probably to the group of Chytridiaceae. One form, indeed, which appears to have been parasitic on the

Studies of Paleozoic Fungi IV: Wall Ultrastructure of Fossil Endogonaceous Chlamydospores

“…It is exceedingly difficult to evaluate fossil hyphae. However, the presumed hyphal knots illustrated by Weiss (1904) as solid black spheres with radiating extensions are not, in our opinion, convincingly fungal, nor do they show distinctive en-dogonaceous features. The "dense tangles of mycelium" illustrated by Andrews and Lenz (1943) are also problematic.…”

“…Fossil hyphae which show some degree of clumping, coiling or looping have also been reported (Weiss, 1904;Andrews and Lenz, 1943) and coiled intracellular hyphae are characteristic of certain VA mycorrhizae (Cox and Sanders, 1974;Kinden and Brown, 1975a, b;Brown and King, 1982;Taber and Strong, 1982). It is exceedingly difficult to evaluate fossil hyphae.…”

“…Such structures are probably best known from the Devonian Rhynie Chert (Kidston and Lang, 1921), and have aroused considerable interest because of their resemblance to extant vesiculararbuscular (VA) mycorrhizal fungi. Butler (1939) was perhaps the first to suggest that such bodies were fossil representatives of the modern Endogonaceae, while others have reported similar fungi and considered the possibility of endomycorrhizal relationships in the Paleozoic (Weiss, 1904;Lignier, 1906;Osborn, 1909;Halket, 1930;Zimmermann, 1933;Andrews and Lenz, 1943;Wolf and Wolf, 1947;Kelly, 1950;Boullard and Lemoigne, 1971). More recently, Pirozynski and Malloch (1975) have argued for the presence of VA mycorrhizae associated with plants in the Paleozoic, and have suggested that the establishment of mycorrhizal relationships was a major factor in the development of the vascular land flora.…”

Recent advances in palaeomycology

“…Supposed Palaeozoic arbuscles were reported by Osborn (1909), Halket (1930, Lignier (1906) and Zimmermann (1933) but Cridland (1962 discounted these reports and interpreted the putative arbuscles as secretory material that became fibrillar as it dried. Similarly, coiled or looping hyphae have been reported by Weiss (1904) and Andrews & Lenz (1943) but their appearance suggests a non-fungal origin (Stubblefied et al, 1985 c). Vesicles/chlamydospores reminiscent of extant VAM fungi have also been described from the fossil record (e.g.…”

A fungal community in plant tissue from the Lower Coal Measures (Langsettian, Lower Pennsylvanian) of Great Britain

“…Co-occurring with the plants are various types of fungi. Although the presence of fungi in the coal balls was noted in several early studies, including Cash & Hick (1879), Williamson (e.g., 1880Williamson (e.g., , 1881Williamson (e.g., , 1883, Weiss (1904), and Ellis (1918), their diversity and significance as ecosystem constituents have not been fully appreciated.…”