Rhizina undulata

Rhizina undulata
Scientific classification
Kingdom: Fungi
Subkingdom: Dikarya
Division: Ascomycota
Class: Pezizomycetes
Order: Pezizales
Family: Rhizinaceae
Genus: Rhizina
Species: R. undulata
Binomial name
Rhizina undulata
Fr. (1815)

Rhizina undulata, commonly known as the pine firefungus,[1] is a species of fungi in the genus Rhizina, family Rhizinaceae. The fruiting bodies are dark purple brown with a bright yellow margin, crust-like and attached to the growing surface by numerous yellow rhizoids. R. undulata has a cosmopolitan distribution, and commonly occurs on clearings or burned areas throughout central and northern Europe and North America. It is parasitic on conifer seedlings, and has caused considerable damage to tree plantations worldwide.

Contents

Description

Fruiting bodies, which may be up to 6 centimetres (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. The hymenium is dark purple brown to blackish, while the margin is pale yellow (like the underside), and wavy and irregular.

Microscopic characteristics

The spores are fusoid, apiculate, minutely verricose at maturity, with one or two oil drops, and have dimensions of 30–40 × 8–11  µm.[2] The asci are roughly cylindrical, and 250–280 × 14–18  µm.[3] 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 um wide.[2]

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.[4] 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), the spores may lie dormant in soil for two years.[5] 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) for paving new roads has also been observed to cause the same deleterious effect on neighboring conifers.[6]

References

  1. ^ "Rogers Mushrooms | Mushroom Pictures & Mushroom Reference". http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~6734~gid~~source~gallerydefault.asp. Retrieved 2009-02-12. 
  2. ^ a b Tylutki, Edmund E. (1979). Mushrooms of Idaho and the Pacific Northwest. Moscow: University Press of Idaho. p. 96. ISBN 0-89301-062-6. 
  3. ^ Samuelson DA. (1978). "Asci of the Pezizales. 6. Apical appratus of Morchella esculenta, Helvella crispa, and Rhizina undulata". Canadian Journal of Botany 56(24): 3069–3082.
  4. ^ Ginns JH. (1968). "Rhizina undulata pathogenic on Douglas Fir seedlings in western North America". Plant Disease Reporter 52(7): 579–580.
  5. ^ Hardison JR. (1976). "Fire and flame for plant disease control". Annual Review of Phytopathology 14: 355–379.
  6. ^ Gremmen J. (1971). "Rhizina undulata: A review of research in the Netherlands". Euopean Journal of Forest Pathology 1(1): 1–6.

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