Flowers up to 40mm. Florets not projecting.
However lower leaves longer than wide so possibly an intermediate burdock.
No interactions present.
I am interested to know where the idea that the leaf dimensions are a distinguishing feature comes from. Never heard it other than on iSpot. John Poland's Vegetative Key does not use it or even mention A. lappa curiously as its solid petioles are a give-away.
Collins Complete Guide to British Wild Flowers says that lesser burdock's basal leaves are "longer than wide" while greater burdock's basal leaves are "as long as wide".
That's the book I take out with me for reference.
It is a useful book, but I would place greater reliance on the hollow stems of basal leaves in minus agg. and solid for lappa. You can sometimes tell by squeezing, but there is no harm in cutting one leaf off. You will see a clear floral difference in lappa when you find it!
I will keep that in mind. When plants are locally common I can examine them repeatedly and over time which helps. Burdock is one I rarely see. Getting it wrong helps me to look more closely at things. When I find lappa I'll be ready for it :)
Lat/Lng: 54.169, -0.6682
OS grid ref: SE870756
In shady woodland