Clumps of irregular swellings affecting all parts of a single branch of a stem, smooth and hairless in spring but apparently drying to a rough and irregular brown in the fall. Observed on Sisymbrium irio and Brassica nigra, both Eurasian weeds in North America; likely also found on other Brassicaceae plants. The inducer is uknown. The swelling symptoms may be consistent with what Ditylenchus dipsaci is known to induce on some of its many host plants, which include some Brassicas. However, most if not all observations of this gall are associated with a beetle larva, adult, or emergence hole, suggesting that a beetle may be the inducer. It is also possible that both organisms, or something else entirely, is responsible for the original induction of the gall.

Another useful tool is this European key to gallers on Sisymbrium. Of the species listed in the key, Albugo candida is known to be present in North America.

The type observation on BugGuide.

- Gallformers Contributors: (2023) Gallformers ID Notes^©