Cordyceps hawkesii (G.R.Gray) Cooke

Common name: Vegetable Caterpillar.

Description: Forms club-shaped, sometimes irregular fruiting bodies projecting about 812 cm above the ground. The club section of the fungus is 12 cm thick, about 58 cm long and is bay-brown; the stem is much paler in colour and about 1 cm thick. The fungus is apparently growing on the ground, but careful excavation shows that the stem passes underground and is attached to a mummified body of a caterpillar. Very similar in size to C. gunnii and may even grow beside it, but the fruiting body is brown not green, and there are also other microscopic characters which separate the two.

The spores are very difficult to find intact as they are thread-like and break apart into smaller sections very rapidly. These smaller sections function as fully viable spores and measure 35 × 23 µm; they are more or less cylindrical, smooth and colourless.

Substratum: Apparently on soil among litter, but actually parasitic on the large caterpillars of the hawkmoth (Oxycanus spp.) and also on species of Trictena (swift moths).

Distribution: Known from Queensland, New South Wales and Victoria.

Notes: These curious fungi are often destroyed before the collector realises what has been found. The fungus appears to be growing directly on the ground, but is actually attached to the mummified body of a large caterpillar that has burrowed underground in order to pupate. There has been no major recent revision of these fascinating fungi in Australia, and there is some doubt as to the interpretation of this species. However, this brown, entomophagous fungus has been collected in numerous locations. Another Australian species, C. militaris, is bright orange and produces fruiting structures about 34 cm high (see also C. gunnii).