Dandelion stalk tumors?

October 23, 2022 7:59 AM

Back in the 90s, on the north coast of California, we used to regularly find dandelions (or maybe a false dandelion species) with certain stalks that were irregularly fattened — almost like tumors or burls. We’d pull the flower tops off and put them in our dollhouses as alien visitors. I can’t seem to find ANY info online about this phenomenon. Anyone know what this is called, or what caused it?
posted by alycoop to Science & Nature (6 answers total)

Best answer: Sounds like a gall. They're usually caused by parasitoid wasps or sawflys. The wasp larvae develop in these galls. Goldenrod galls are pretty common and much easier to do an image search on than other plants. If you do an image search for a goldenrod gall, does it resemble what you remember?
posted by ockmockbock at 8:21 AM on October 23, 2022

Oh I bet it’s fasciation! (although having reread I realise I got a bit excited and maybe it’s galls instead)
posted by lokta at 8:29 AM on October 23, 2022

Yes, fasciation. Dandelions are one of the most common flowers that this happens in.
posted by drlith at 8:41 AM on October 23, 2022

Response by poster: Ah! Seems to be the catsear gall wasp. Thank you!
posted by alycoop at 12:55 PM on October 23, 2022 [1 favorite]

Response by poster: Fascination is really cool; not what i was thinking of, but definitely something i’m going to be reading more about now :)
posted by alycoop at 12:56 PM on October 23, 2022 [1 favorite]

the ones in my yard that get sprayed with Weed-B-Gon look like way you are describing.
posted by ArgentCorvid at 6:16 PM on October 23, 2022