''Cyttaria gunnii'', commonly known as the myrtle orange or beech orange, is an orange-white coloured and edible

ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defi ...

fungus native to Australia and New Zealand. It is a specific parasite of myrtle beech ('' Nothofagus cunninghamii'') trees.

History

English botanist Miles Joseph Berkeley described the beech orange in 1848. In 1886, a New Zealand fungus similar to the beech orange was described as ''Cyttaria purdiei''; later, however, the two species were assumed to be the same. A

molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

study has now found the Australian and New Zealand fungi known as ''C. gunnii'' to be two distinct species. New Zealand populations are restricted to '' Nothofagus menziesii'' while the Australian ones are only found on '' Nothofagus cunninghamii'' and are hence found in southern Victoria and Tasmania. The 1889 book 'The Useful Native Plants of Australia records that "This edible fungus is found on the branches of Fagus Cunnittghamii, or native Beech. Tasmania." The evolution of the genus parallels that of the host genus '' Nothofagus''; hence ''C. septentrionalis'', the closest relative, parasitises Antarctic beech ('' Nothofagus moorei''), the closest relative of myrtle beech. Ancestors of the two species are thought to have diverged from the South American and New Zealand ''Cyttaria'' species between 28 and 44 million years ago.

Appearance and uses

The fungi form globose woody galls on their host trees, though they do not appear to spread through them. They are perennial and produce crops of fruit bodies annually. Said to resemble bunches of grapes, the fruit bodies appear in clusters in late spring and summer (November to January). Globular or pear-shaped, these can reach 2.5 cm (1 in) in diameter. They are covered by a membrane that bursts, uncovering a network of concavities. The spore print is black and the

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

s measure 12 by 7–12

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

. Aboriginal Australians have used the fruit bodies as food. The fruits have a consistency akin to jelly and are reportedly pleasant-tasting.

References

{{Taxonbar, from=Q10465417 Edible fungi Fungi described in 1845 Fungi native to Australia Fungi of New Zealand Parasitic fungi Leotiomycetes Taxa named by Miles Joseph Berkeley