Spruce Pollen on Lake Iliamna

Asked August 6, 2018, 4:22 AM EDT

Every few years yellow/orange pollen forms on some spruce trees. When it releases and gets windblown streaks of it float on the lake water. What is this pollen? Why is it only on some trees? Why does it occur in some years, not all? Two pics are attached to help with the id.

Alaska spruce pollen

4 Responses

I don't think this is pollen. I suspect it is some kind of fungal blight. Do you see this uniformly on the tree or most concentrated around the cones?

Thanks Stephen. The yellow/orange powder is all over the tree from low to high but mostly on the outside ends of the branches. There are no cones on the trees that I see, altho there were cones earlier but most if not all were blown to the ground on windy days. There are spruce trees all over the village. Not all have the "blight". It's very inconsistent. What is the blight called? If I see a picture I can compare it to what I'm seeing here. And what causes the blight? I'm attaching a few more pics.

Hello,

Yes, this isn't spruce pollen, but rather spores from fungus called spruce needle rust. You can read more about it here:

Needle rust does not usually kill trees (though it can if affected for several years), but it does stress trees.

This fungus requires two host plants to complete its lifecycle, spruce and Labrador tea. I would suspect you would see more rust on spruce in areas near Labrador tea plants than you would spruce farther from Labrador tea. There are other factors that may affect why some trees are infected and not others such as tree size and how full or dense the branches and needles are.


Thanks Jesse for the informative response. Very interesting. Especially the connection between the spruce trees and Labrador tea.