I now believe the plant is sticky willow, but I haven't been able to find
it's scientific name. (A plant that has seeds that can stick to clothes.)
If someone can tell me its proper name I can do more reading up about it.

Galium aparine, but I don't see it in your photographs. (Whorled
foliage, hairy stems (will also stick to clothes) and small white
flowers.) The 'standard' vernacular name is cleavers. I knew it as
sticky willow as a kid, but I've elsewhere seen it as sticky willy.
--
Stewart Robert Hinsley