Would like some help identifying this plant. This has been growing next to our pine tree. It has become very large and we don't know if we should remove it. Thank you!
We also have A. minus in this region. According to Flora of the Pacific Northwest - Second Edition (2018, University of Washington Press, Seattle) its distinguishing features include flower heads in raceme-like arrangements with stalks to 9.5 cm long, leaf stalks hollow at the base and leaves to 60 cm long.
According to this website: Arctium lappa Linnaeus "The dense uncinate phyllaries of the involucre are an excellent characteristic for identification, particularly when the fruits are mature. It is quite easy to differentiate from Arctium minus, for the later, the flower heads have a much shorter peduncle, at time nearly absent. The flower heads of Arctium lappa are also quite bigger that those of Arctium minus, 2.5 cm and up to 4 cm, versus less than 2 cm. When not in flower nor in fruits, it is anyway always simple to differenctiate Arctium lappa from Arctium minus, the petioles of the later are hollow, those of Arctium lappa are not." So, check the petioles!
