Observation: Plant pathology...........

Pine... 

gall rust....fungal disease.......

For quite a long time, I wondered what these nodular, spheroid bulges on the pine branches are. Only recently, I learned these rust colored masses are a kind of gall, caused by fungal pathogens. If unchecked, they can kill the trees.

Peach...
Leaf curl disease of ...caused by Taphrina deformans......

Eucalyptus.....
galls...

another kind...

Coral...
Rot...

Ornamental plum...
Leaf bleach..

Lilly pilly (Syzigium)...
Psyllid..

Sycamore...

Indian hawthorn...
Entomosporium leaf spots..

Citrus...
A kind of miner..

Aloe...
Its a mite-caused gall..

Its signalling gone wrong...just like human tumors..

Coyote Bush (Baccharis pilularis)...
Affected by gall..

It was sad to see this coral tree undergone systemic rotting and on the verge of dying...only the year before, it was green and blooming...

Some rot fungi...........

Seen several big trees gradually succumbing to trees...Like this cottonwood......

Seen young Australian willow die of mushroom growth.. Its understandable as mushroom constantly produce lignin-degrading enzyme destroying plant barks...