Weird plant on Leslie Street Spit - What is it?

[Andreas Jonsson]

Walking around on Leslie street spit the other day I noticed a plant of some sort, a grass I think, that grows a hard bulb, about the size of a large cherry (see pictures below). Presumably the bulb is a container for seeds. Anyway, most of the bulbs I saw had a tiny hole in them (last picture below). I was wondering if anybody knows what plant this is, and who's making the holes!? A bird perhaps (I know american tree sparrows have been roaming the area all winter in search for seeds) or some some sort of insect? Interesting stuff, at least to me.

[GStuart]

I can't tell you what the plant is, but it is usually something common like goldenrod.  The reason for the bulb is that a parasitic insect has laid an egg in the stem and the plant has swollen around the larva.  It was probably laid by some type of gall wasp.

[Andreas Jonsson]

Wow, interesting. Thanks GStuart.

[Cody]

There are alot of these near the Grimsby Airport, in the far right field, however you need permission from the owners to go there.

[AJ]

Follow this link for all you ever wanted to know about these galls:

http://www.fcps.edu/islandcreekes/ecolo ... ll_fly.htm