 We're going to switch gears and go from the rusts to some other stem diseases. The next we're going to talk about is chestnut blight. And this is another introduced disease in the United States and has pretty much eliminated American chestnut from the eastern U.S. And it's difficult in trying to identify whether you have chestnut blight or not. We have some leaves of actually Chinese chestnut which is very similar to American chestnut and the burrs of which the nuts are produced. But I have a number of samples here of chestnut blight on American chestnut and depending upon the size of the stem and the age of the stem and the age of the tree is what happens. The fungus enters the stem and it causes a canker and we've talked about cankers before. And the canker is, the fungus is killing the cambium and one unique thing about this fungus is that it's orange and in many cases results in the bark to turn orange like we see here. So it's killed this and the fungus is moving through the bark and it's creating this orange discoloration and we can see that here as well. It's creating this orange discoloration, again, healthy stem and then the fungus here is fruiting. Now the fungus will produce these little orange dots sometimes and that's where it's fruiting from and sometimes you'll see little orange dots if you take your hand lens and look. It will also do this and this one's a little different. It's hard to see the orange discoloration but it's causing a canker and the trees respond a little bit differently. And on this one here too it's causing a canker or a swelling and again there is some orange little dots here. And one of the best ways to identify this is the orange discoloration. Sometimes you'll see this canker, sometimes you'll see this cracking on the bark and like this here, cracking on the bark but ideally you look for the orange discoloration in the bark and you look for this cracking or this dead part and hopefully be able to identify that this is a piece of chestnut and maybe you'll have a chestnut leaf and a chestnut burr and once you see that, that has to be a chestnut blight.