Conks of Phellinus kawakamii are produced near ground level,
where they may be covered by leaf litter. This may account in part for their
lack of discovery until quite recently.A new heartwood decaying fungus was found by Galen Kawakami, state forester on Kaua‘i. Charles Hodges, a forest pathologist now retired from the USDA Forest Service, together with coworkers, described the fungus as Phellinus kawakamii (Larsen et al., 1985). The fungus causes rot in the butt portion of mature koa (Acacia koa) and casuarina (Casuarina equisetifolia). The disease has been found thus far on the islands of Kaua‘i, Oahu, and Hawai‘i. Koa is an endemic, highly valued tree, whereas casuarina was introduced from Australia and is widely planted in Hawai‘i as a shade tree and for use in windbreaks.
The perennial conks (fruiting bodies) are unusually large, measuring 30-40(-70) x 10-20(-30) x 5-10(-20) cm. At first they are bright ferruginous brown, later becoming a dull brown. The conks occur exclusively at the root collar and usually are obscured by litter. This may account for their escape from notice until their relatively recent discovery. Following Hurricane Iniki in 1992, which was particularly devastating to forests on Kaua‘i, numerous broken trunks of koa showed that internal decay by P. kawakamii was more common in koa forests than had been previously known.
Conks of Phellinus kawakamii are produced near ground level,
where they may be covered by leaf litter. This may account in part for their
lack of discovery until quite recently.
Large perennial conks of P.
kawakamii and white mycelial strands in infected wood (All photos by C. Hodges).