I agree with everything imafan said. But just because I am a total nerd/ garden geek, I find it interesting that phytophthora is not actually a fungus (though it used to be considered such in the past). It is one of those fascinating creatures that is neither plant nor animal nor fungus, but its own kind of thing:
Phytophthora is a genus of the Oomycetes (water molds) which, through convergent evolution, have similarities to fungi. However, oomycetes are not fungi (as had been earlier thought), but are part of Stramenopiles, a kingdom distinct from plants, fungi, and animals that also includes diatoms and golden-brown and brown algae, such as kelp.
Who wooda thunk it? The phytophthora organism is closer related to kelp than to the fungi it resembles!
Ain't nature grand!?