Sick Goosegrass

[aeshna5]

I've noticed recently in several totally different places Goosegrass, Galium aparine, looking very sick with shrivelled leaves. It's obviously a natural agent causing the distortion but does anyone know what the causative organism is?

[AlanS]

Originally Posted by aeshna5

I've noticed recently in several totally different places Goosegrass, Galium aparine, looking very sick with shrivelled leaves. It's obviously a natural agent causing the distortion but does anyone know what the causative organism is?

Hmm, perhaps whatever it is should be marketed?

Actually, I believe I do know. If the leaves are shrivelled and distorted, with the margins conspicuously inrolled, then it is the work of a gall-forming fly, Cecidophyes galii.

If, on the other hand, the leaves are pale and weak, it would be likely to be the powdery mildew, Erysiphe galii - which isn't so conspicuous as most powdery mildews but does seem to weaken the plant quite significantly.

(Mental note to self, next time I see E. galii, bring some back to introduce to the garden.)


Alan

[aeshna5]

Thanks Alan- I had a feeling you might be able to resolve this for me. From your descriptions it sounds very much like the gall-forming fly!

[Wild-Woman]

We get Goosegrass growing in the garden every year. It seems to grow very rapidly and die rapidly. Just got millions of the burrs everywhere. Thought that was normal.
Perhaps ours is sick too!