Showing posts with label Hawthorn Cedar Rust. Show all posts
Showing posts with label Hawthorn Cedar Rust. Show all posts

Sunday, August 15, 2010

Hawthorn Cedar Rust - Follow-up

A few months ago I mentioned the Hawthorn Cedar Rust that was attacking the Dwarf Hawthorn, Crataegus uniflora. The rust has been very detrimental to many of the hawthorn fruits. Fruiting bodies have recently opened and deposited spores onto the leaf below. Fortunately for the hawthorn, these spores are only capable of infecting Eastern Red Cedar, the alternate host in the rust life cycle.

Leaves have also suffered from the attack of the rust. Brown patches and edges are the most evident results.

Twigs that showed rust damage in May have developed these hard growths. This is a rather odd looking growth and looks as though the plant was trying to defend itself by growing a woody barrier between itself and the rust. As a defense against fungal invaders, many plants will use this type of defense and the result is a canker or odd growth mass at the point of infection. Maybe I don’t have to be so worried about the Cedar Rust killing off these uncommon plants.

As a whole, the shrubs look healthy. Fruit production was low this year, but the plant itself doesn’t seem to have suffered.

A few small yellow spots are all that is left of the infection on most of the leaves.

There were even several healthy fruits produced. My visit to the Dwarf Hawthorns had me in a really good mood. That changed slightly when I pulled my arm back a little bit too far while taking this shot.

I felt leaves brushing the back of my arm and then there were a couple of pin pricks. At first I thought it was just those pesky ants trying to protect some food source they had found on the hawthorn leaves. I ignored it and went on with my picture taking, until a wash of hot prickles started to spread from my elbow to my shoulder. I had managed push against this innocent looking mass of fluff, commonly known as a Flannel Moth larva. Beneath the fluff is a collection of poisoned spines that produces an effect similar to stinging nettles. As I type this, about 12 hours after the encounter, my arm is still sore and I have a nice red welt. At least I now know how I react to this particular poison. It probably wouldn’t have been this bad if I’d had the sense to pull away at the first sting.