Oudemansiella australis

Oudemansiella australis
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Physalacriaceae
Genus:	Oudemansiella
Species:	O. australis
Binomial name
Oudemansiella australis G.Stev. & G.M.Taylor (1964)

Oudemansiella australis is a species of gilled mushroom in the Physalacriaceae family. It is found in Australiasia, where it grows on rotting wood. It produces fruit bodies that are white, with caps up to 5.5 cm (2.2 in) in diameter, attached to short, thick stems.

Taxonomy and classification

The species was reported as new to science by Greta Stevenson and G.M. Taylor in a 1964 publication, based on a specimen found in March, 1961.^[1] According to the 1986 arrangement of Pegler and Young, based largely on spore structure, Oudemansiella australis is classified in the section Oudemansiella of genus Oudemansiella, along with the species O. mucida, O. venesolamellata, and O. canarii.^[2] In a more recent classification proposed by Yang and colleagues, O. australis is in section Oudemansiella, which contains tropical to south temperate species, such as O. platensis, O. canarii and O. crassifolia. These species are characterised by having an ixotrichoderm cap cuticle, meaning it is made of gelatinized filamentous hyphae of different lengths arranged in roughly parallel fashion. These hyphae are often mixed with inflated cells that usually occur in chains.^[3]

New Zealand mycologist Geoff Ridley has proposed the common name "porcelain slimecap" for the mushroom.^[4]

Description

Oudemansiella australis mushrooms have a cap that is 3–5.5 cm (1.2–2.2 in) in diameter, and initially white becoming a light yellowish brown (fawn) in age. It has a convex shape, but splits at the margins. The cap cuticle splits irregularly to reveal firm white flesh underneath. The gills are adnate, powdery white, and moderately distantly spaced. They are long and short intercalated, with deep with ribs at the base. The stem is 2.5 cm (1.0 in) long by 0.6–1 cm (0.2–0.4 in) thick, attached off-centre to the cap. It is white on the upper part, changing to fawn around the swollen base. The flesh is solid, white, and silky.^[1]

The spore print is white. Spores are spherical or nearly so, measuring 24 by 21 µm, with thick walls (about 1 µm). They are non-amyloid, and have a prominent hilar appendix (a depression in the surface where the spore was once connected to the sterigmata).^[1][2]

Habitat and distribution

The fungus grows on rotting wood. The first recorded collection was made in the open near a forest in Wainui Valley, Wellington.^[1] It has since been found in Australia and Papua New Guinea.^[5]

References

1. ^ ^{a b c d} Stevenson G. (1964). "The Agaricales of New Zealand: V". Kew Bulletin 19 (1): 1–59. http://www.jstor.org/stable/4108283.  (subscription required)
2. ^ ^{a b} Pegler DN, Young TWK. (1986). "Classification of Oudemansiella (Basidiomycota, Tricholomataceae), with special reference to spore structure". Transactions of the British Mycological Society 87 (4): 583–602. http://www.cybertruffle.org.uk/cyberliber/59351/0087/004/0583.htm. 
3. ^ Yang Z-L, Zhang L-F, Mueller GM, Kost GW, Rexer K-H. (2009). "A new systematic arrangement of the genus Oudemansiella s. str. (Physalacriaceae, Agaricales)". Mycosystema 28 (1): 1–13. 
4. ^ Ridley G. (2004). "A system for the development of English language names for agarics and boletes in New Zealand". Australasian Mycologist 23 (1): 27–30. http://australasianmycology.com/pages/pdf/23/1/27.pdf. 
5. ^ Mueller GM, Wu Q-X, Huang Y-Q, Guo S-Y, Aldana-Gomez R, Vilgalys R. (2001). "Assessing biogeographic relationships between North American and Chinese macrofungi". Journal of Biogeography 28 (2). http://www.jstor.org/stable/2656103.  (subscription required)