Rhizina undulata
| Rhizina undulata | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Pezizomycetes |
| Order: | Pezizales |
| Family: | Rhizinaceae |
| Genus: | Rhizina |
| Species: | R. undulata |
| Binomial name | |
| Rhizina undulata Fr. (1815)[1] | |
| Synonyms[2] | |
Rhizina undulata, commonly known as the doughnut fungus or the pine firefungus, is a species of fungus in the genus Rhizina, family Rhizinaceae. The fruit bodies are dark purple brown with a bright yellow margin, crust-like and attached to the growing surface by numerous root-like yellow rhizoids. R. undulata has a cosmopolitan distribution, and commonly occurs on clearings or burned areas throughout central and northern Europe, North America, northern Asia, and southern Africa. It is parasitic on conifer seedlings, and has caused considerable damage to tree plantations worldwide.
Taxonomy
The fungus was first described in 1774 as Helvella inflata by the German polymath Jacob Christian Schäffer. It acquired its current name in 1815 by virtue of its publication in Elias Magnus Fries's Observationes mycologicae.[2]
The specific epithet undulata means "wavy" or "undulating". Common names that have been used to refer to the species include "crust-like cup", "pine-fire cushion",[4] "doughnut fungus",[5] and "pine firefungus".[6]
Description
Fruit bodies, which may be up to 6 cm (2.4 in) wide, are flat, with irregular lobes, and are attached to the growing surface on the entire lower side by numerous whitish to yellowish rhizoids resembling plants roots. The hymenium is dark purple brown to blackish, while the margin is pale yellow (like the underside), and wavy and irregular.[7] The fruit body has a leathery texture when old.[8]
The spores of Rhizina undulata are fusiform (fuse-shaped), apiculate, minutely verricose at maturity, with one or two oil drops, and have dimensions of 30–40 by 8–11 µm.[7] The asci are roughly cylindrical, and 250–280 by 14–18 µm.[9] Like most other Pezizales, the asci open at maturity by means of an apical, lid-like flap of tissue termed an operculum. The paraphyses are slightly club-shaped, tips encrusted with tubular setae, thin-walled, brown, aseptate and parallel-sided, tapering to a blunt point, and are 7–11 µm wide.[7]
Similar species
Disciotis venosa has an overall similar blistered appearance, but can be distinguished by its distinct bleach-like odor. Discina ancilis bears a general resemblance to Rhizina undulata, but its fruit bodies lack rhizoids on their undersurface, and are attached to the substrate at a central point.[10]
Habitat and distribution
This is a widespread fungus that grows on burned soil or conifer debris. Although it is regarded as a saprobic species, it can also attack conifers of varying age parasitically.[11] Rhizina undulata attack in recently established conifer plantations in areas where slash burning after clear felling has been performed is a well-known phenomenon. Because the optimum temperature for spore germination is high (35–45 °C (95–113 °F)), the spores may lie dormant in soil for two years.[12] As a result of these fires, the underlying soil is heated so that suitable conditions are created for the germination of ascospores. The use of hot asphalt (110–130 °C (230–266 °F)) for paving new roads has also been observed to cause the same deleterious effect on neighboring conifers.[13] Rhizina undulata has been recorded in northern Asia, Europe, and North America. It has been introduced into southern Africa.[10]
References
- ↑ Fries EM. (1815). "Observationes mycologicae" (in Latin) 1. Copenhagen: Gerhard Bonnier. p. 164.
- ↑ 2.0 2.1 "GSD Species Synonymy: Rhizina undulata Fr.". Species Fungorum. CAB International. Retrieved 2014-01-16.
- ↑ Schaeffer JC. (1774). Fungorum qui in Bavaria et Palatinatu circa Ratisbonam nascuntur Icones (in Latin) 4. Regensburg.
- ↑ Roody WC. (2003). Mushrooms of West Virginia and the Central Appalachians. Lexington, Kentucky: University Press of Kentucky. p. 468. ISBN 978-0-8131-9039-6.
- ↑ McKnight VB, McKnight KH. (1987). A Field Guide to Mushrooms: North America. Peterson Field Guides. Boston, Massachusetts: Houghton Mifflin. p. 54. ISBN 978-0-395-91090-0.
- ↑ Phillips R. "Rhizina undulata". Rogers Plants. Retrieved 2009-02-12.
- ↑ 7.0 7.1 7.2 Tylutki EE. (1979). Mushrooms of Idaho and the Pacific Northwest. Moscow, Idaho: University Press of Idaho. p. 96. ISBN 0-89301-062-6.
- ↑ Courtecuisse R. (1999). "Mushrooms of Britain and Europe". Collins Wildlife Trust Guides. London, UK: Harpercollins. p. 292. ISBN 978-0-00-220012-7.
- ↑ Samuelson DA. (1978). "Asci of the Pezizales. 6. Apical apparatus of Morchella esculenta, Helvella crispa, and Rhizina undulata". Canadian Journal of Botany 56 (24): 3069–82. doi:10.1139/b78-370.
- ↑ 10.0 10.1 Roberts P, Evans S. (2011). The Book of Fungi. Chicago, Illinois: University of Chicago Press. p. 585. ISBN 978-0-22-672117-0.
- ↑ Ginns JH. (1968). "Rhizina undulata pathogenic on Douglas fir seedlings in western North America". Plant Disease Reporter 52 (7): 579–80.
- ↑ Hardison JR. (1976). "Fire and flame for plant disease control". Annual Review of Phytopathology 14: 355–79. doi:10.1146/annurev.py.14.090176.002035.
- ↑ Gremmen J. (1971). "Rhizina undulata: A review of research in the Netherlands". Euopean Journal of Forest Pathology 1 (1): 1–6. doi:10.1111/j.1439-0329.1971.tb00283.x.