This is not exactly a gardening question, but maybe someone here will
know: what is capable of causing large galls on henbit (Lamium
amplexicaule)? I have a lawn that I keep on the long side and never
treat with weed killers, so I get plenty of henbit that flowers this
time of year. Only this year many of the henbit plants are bearing a
bizarre gall that I've never seen on them before. The galls are
greenish, up to 1 cm or more in diameter, and sometimes more than one
are fused together, on the stalks under the leaves. When cut open, they
have an internal structure something like that of small cucurbits or
gourds.

Anyone know what this might be?

--
David Sewell, University of Virginia
Charlottesville, VA USA