Claustula fischeri K.M. Curtis 1926
Fischer's egg
General status: Native non-endemic (known from Tasmania; Status in Tasmania similar to NZ
Population: <250? Area 10-100 ha? Known from 2 areas only
Decline: Population ? stable. Probably reduced by human impact on beech forest
Distribution: Nelson-Marlborough and Wellington
Biology
The truffleoid (truffle-like) fungus Claustula fischeri is proposed for consideration as threatened because it is known from only 2 sites. In part this must reflect collecting activity, as collection of truffleoid fungi requires special skills and is time-consuming. Nevertheless, there are sufficient collections of these fungi to indicate that the species is uncommon (ie found once in about 1500 collections of truffleoid fungi spread amongst about 100 taxa).
Claustula fischeri has traditionally been placed in in its own family (Claustulaceae) in the order Phallales (stinkhorns etc). Like many truffleoid fungi it produces a more or less round brownish fruit body 2-3 cm across. It classification in its own family reflects its unique mode of dehiscense; the outer brown gelatinous layer splits open to reveal a pure white 'egg'. The egg per se does not open further and the spores are borne inside the 'egg'. It is not known what the natural dispersal agents of Claustula are but it is tempting to propose that along with many other NZ truffleoid species it is adapted to bird dispersal (Beever 1999). The new Dictionary of Fungi places this species in the family Phallaceae, but I consider this premature in the absence of molecular data.
The biology of Claustula is poorly known. It is probably ectomycorrhizal on beech and/or tea-tree.
The known locations for this fungus are Fringed Hill and Dun Mt track in Nelson, and Rocky Hill in the Wairarapa. At the one site I am familiar with (Fringed Hill) it is associated with Nothofagus fusca on a bush margin at risk from fire.
References:
Beever RE 1999. Dispersal of New Zealand sequestrate fungi. Abstracts p. 190, 9th International Congress of Mycology, Sydney, 16-20 August 1999.
Curtis KM 1926. The morphology of Claustula fischeri, gen. et sp. nov. A new genus of phalloid affinity. Annals of Botany 40: 471-477 London:.
Mills AK, et al. 1997. Claustula: the forgotten phalloid. Mycologist 11: 31-35.