Other Diseases

In addition to the diseases of native plants illustrated on the accompanying pages, several other diseases and apparent abnormalities have been observed.  In some (but not all) cases these have received little attention and little is known about them.   Most of the following host plants are endemic, but some are indigenous species to Hawai‘i:

  Collapse of stem tissue (arrow) of seedlings of maile (Alyxia oliviformis) associated with an unidentified fungus.

  The smut fungus Sphacelotheca monilifera (=Ustilago monilifera), an introduced pathogen that infects and destroys seed heads of pili grass (Heteropogon contortus), a species possibly indigenous to Hawai‘i.  The fruit (i.e., "seeds") are replaced by black masses of fungus spores, which are dispersed by the wind.

   An unidentified leaf spot on leaves of ‘ohi‘a (Metrodsideros polymorpoha).

   A leaf spot disease of ‘ohi‘a associated with an unidentified species of Mycosphaerella.

   Leaf spot of kauila (Alphitonia ponderosa) caused by an unidentified species of Cercospora.

   Leaf spot of kawa‘u (Ilex anomala) caused by an unidentified species of Mycosphaerella.

   Leaf spot and marginal necrosis of soapberry (Sapindus saponaria) assoicated with, among other fungi, Mycosphaerella sp.

   Leaf spot of aulu (Pisonia sandwicensis) caused by an unidentified fungus.  [Note:  Barr and Hodges (1987) described a leaf spotting fungus on P. sandwicensis as a new species, Stigmochora variegata.  However, the leaf spot referred to here appears to be caused by a another pathogen.]

   Powdery mildew infection on leaves of ‘ohelo (Vaccinium reticulatum) caused by an undescribed species of Oidium.

   Leaf spot of tree ‘ohelo (Vaccinium calycinum) caused by an unidentified species of Mycosphaerella.

    Leaf spot from an unknown cause on upper surface (left), and lower surface (right) of Crytandra platyphylla.

   Dieback of pukiawe (Styphelia tameiameiae) from an unknown cause.  This indigenous species is a major vegetational component of native mid to upper elevation shrublands.

   A large conk of an unidentified species of  the genus Ganoderma on a lower trunk of koa (Acacia koa).  Conks (fruiting bodies) on the exterior such as this indicate extensive damage to the interior of the trunk caused by the wood decaying fungus.

A leaf spotting fungus, Gloeocoryneum hawaiiense, on koa (Acacia koa) was described as a new species by Sutton and Hodges (1983) for which no photograph is available.  The fungus produces small, dark conidiomata (fruiting bodies), typically serially arranged on the leaf surface.