GALL
the root collar and roots are strongly swollen, spindle-shaped; there is no gall chamber.

HOST PLANTS
Brassicaceae, broadly oligophagous:

Aethionema saxatile; Alliaria petiolata; Alyssoides utriculata; Alyssum alyssoides, desertorum, montanum; Arabidopsis arenosa, suecica, thaliana; Arabis; Armoracia rusticana; Aubrieta columnae, deltoidea, pinardii; Aurinia petraea, saxatilis; Barbarea stricta, verna, vulgaris; Berteroa incana; Biscutella auriculata, didyma, laevigata; Brassica oleracea; Braya alpina; Bunias erucago, orientalis; Calepina irregularis; Camelina; Capsella bursa-pastoris, orientalis, rubella; Cardamine amara, parviflora, pratensis; Cardaria draba; Coclearia anglica, danica, groenlandica, officinalis; Coincya monensis subsp. cheirantho, wrightiis; Conringia orientalis; Crambe abyssinica, maritima, tataria; Descuriania sophia; Diplotaxis erucoides; Draba; Erophila verna; Eruca vesicaria; Erucastrum gallicum, nasturtiifolium; Erysimum cheiranthoides, cheiri, crepidifolium, hieraciifolium, odoratum; Hesperis kotschyana, matronalis, tristis; Hirschfeldia incana; Iberis; Isatis glauca, praecox, tinctoria; Lepidium campestre, coronopus, densiflorum, didymum, ruderale, sativum, viriginium; Lobularia maritima; Lunaria annua, rediviva; Malcolmia africana, flexuosa, maritima, orsiniana subsp. angulifolia; Matthiola incana, longipetala subsp. bicornis, tricuspidata; Myagrum perfoliatum; Nasturtium; Neslia paniculata; Petrocallis pyrenaica; Raphanus raphanistrum & subsp. rostratus, sativus; Rapistrum perenne, rugosum; Rorippa austriaca, islandica, sylvestris; Sinapis alba, arvensis & subsp. allionii; Sisymbrium; Syrenia cana; Thlaspi.

References to Papaver, Reseda and especially Agrostis, Fragaria, Holcus, Lolium by Brandenburger, Klenke & Scholler need further confirmation.

Clubroot disease, caused by the protist pathogen Plasmodiophora brassicae, is responsible for extensive damage to oilseed rape and brassica vegetable crops. ... P. brassicae, grows intracellularly in host root systems and manipulates the development of the belowground parts of the plant to form distinctive galls. Cellular reprograming ... allows the pathogen to acquire host nutrients and secure space for resting spore formation