• Proposed
  • Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Dichomitus newhookii P.K. Buchanan & Ryvarden

Go to another Suggested Species...

Scientific name
Dichomitus newhookii
P.K. Buchanan & Ryvarden
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Under Assessment
Proposed by
Peter Buchanan
Peter Buchanan
Tom May
Peter Buchanan
Anders Dahlberg, Gregory Mueller

Assessment Notes

Taxonomic notes

Dichomitus newhookii PK Buchanan & Ryvarden was established for 2 collections (1955, 1956) previously by G. Cunningham as Poria leucoplaca (Berk.) Cooke (=Dichomitus leucoplacus (Berk.) Ryvarden), a species with smaller pores ((3-)4-5 per mm) and spores (10-14 x 4-5.5 µm). D. newhookii is microscopically distinctive in occasionally septate basidiospores possibly related to spore maturity.

In macroscopic appearance strongly resembles the New Zealand species Perenniporia podocarpi.

Why suggested for a Global Red List Assessment?

New Zealand endemic polypore. Only 2 collections known, both from separate offshore islands. Not re-collected since 1956. maybe seem inconspicuous to non-polypore collectors, but focused collecting of polypores 1940s-1950s produced only 2 specimens and none on mainland.

Geographic range

Endemic New Zealand polypore wood decay fungus. Not recorded on mainland.  Known only from single collections from 2 offshore islands - Great King Is. and Little Barrier Is.

Population and Trends

Unknown.  Of only 2 known collections, both were initially misidentified and deposited in Fungarium PDD under D. leucoplacus.  Intense polypore collecting occurred 1940-1950 (Dingley, Cunningham) and further in 1990s (Buchanan). Not collected since 1956.  Population & trend unknown.

Population Trend:

Habitat and Ecology

On the basis of the 2 known specimens, D. newhookii is a saprobic species on dead wood of Knightia excelsa(?) and Kunzea ericoides. Host range may be greater.


Both island locations have high conservation status, with removal of herbivorous vertebrates, so hosts should be safe on these islands, and both are common and widespread on the mainland. Climate disruption as potential threat? - if habitat is indeed restricted to these 2 islands.

Conservation Actions


Research needed

Further collecting on both islands (permits and access challenging) to confirm survival there, and targeted collecting especially on 2 named hosts on mainland New Zealand.  Phylogenetic study needed, requiring fresh specimens.

Use and Trade



Buchanan, P.K.; Ryvarden, L. 2000: New Zealand polypore fungi: six new species and a redetermination. New Zealand Journal of Botany 38(2): 251-263.

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted