Here is a weed that I'm allergic to, so I endeavor to pull every one of them I see. They smell nasty too. I hate to even get close enough to them to pull, but before I discovered what was causing my allergy I couldn't go to my oasis this time of year without having to take medication. Now I can enjoy it allergy free, except when I pull one of these. My eyes itch and my nose runs when I get near them, but I don't have to take meds to breathe now that there are only one or two around. The other day I pulled a bunch of them (all I could locate) and had to take an allergy pill. Today I located 2 more.
And these next ones have seed pods that are like velcro. I call them cockle-burs.
I don't pull stuff unless I know for sure what it is I'm pulling. You never know, it might turn out to be something wonderful. Some do; some not so much.
UPDATE: A sharp reader of this blog informed me that the noxious weed I'm allergic to is probably Golden Crownbeard (Veresina encelioides), known locally as Cowpen Daisy. So I did some research and discovered that weed, which I'm sure it is, is poisonous to cattle, sheep and goats. It contains toxic galegine. Not good for birds either, apparently. I'll be even more diligent against it now, although it's so invasive nearly worldwide, that it'll be an ongoing battle. Just one more ongoing battle to add to my list.