 Another of the stem diseases we want to discuss are hypoxelin canker. And this is a little bit different than the nectria canker. And we have two examples here. We have hypoxelin canker of oak and hypoxelin canker of aspen. And this particular fungus is interesting. It will infect oak trees. But what it does is it forms this what we call stromata. And what happens is it literally replaces the bark. And this is the fruiting structure. We've talked about fruiting structures and those conchs that grow on the side of the trees. Well, this is the fruiting structure here. In this particular case, it's gray. And here's another portion here. What's happening is the fungus has killed the cambium and it's causing a canker. And it's producing an area for it to produce its spores to go infect other trees. And here's another part here. And we can turn the log over. And we can see this too here is hypoxelin canker. This stromata, as we call it, can be gray. It can be brown. It can be black. I've seen it white. In this particular case, it's not very expansive on the stem. But in many cases, it can replace the whole stem. So this is hypoxelin canker of oak. And then we have a... What makes this a little different is we don't see the rings like we would see on nectria canker. Because the fungus just moves throughout the whole stem. And we see that even here on our hypoxelin canker of aspen. The fungus has entered probably the branch here. And it's killing the cambium and it's causing a canker. And we can see that by the sunken lesion here. And the tree has tried to respond a little bit by forming callus. And then it too produces the stromata. And it's a little bit smaller here on aspen. But this is the fruiting structure of aspen on aspen. And we can see it a little bit here. Here's the fruiting structure. And we can see that this is truly a canker because it is killing the cambium. And the tree is trying to respond. And we do not see the target shaped. There's not a concentric rings around the branch stem like we would see with nectria canker. But we do see death of the cambium and we do see the fruiting structures on aspen.