TYVM for the inputs! I think I would have noticed lavender flowers 7 ft. in the air before. Leaves don't really look the same to me.
Leaning toward L. serriola but may need more pics to be sure, unless those more skilled at investigation & plant anatomy than me are able to tell from these pics. I've been wondering passively, occasionally, for 8 yrs... a few more weeks should be OK, unless I see one here in town in a convenient spot.