Dichotomous table for gallers on Iberis
by Hans Roskam
1a On parts above ground => 5
1b On root collar or on roots => 2
2a On main- or side roots => 3
2b Up to 8 mm long, almost globular, fleshy gall on root collar. Containing a single larva in a central chamber. I. amara: Ceutorhynchus assimilis
3a Short nodular or long cylindrical galls => 4
3b Outside of roots little changed, temporarily bearing white to brown, poppy seed sized cysts. Giant cells develop inside. I. amara, umbellata: Heterodera schachtii
4a Nodular to spindle-shaped galls, a few mm long, mainly on side roots. I. sempervirens: Meloidogyne hapla
4b Up to several cm long spindle-shaped to cylindrical, fleshy galls, usually on side roots. Iberis spp.: Plasmodiophora brassicae
5a On stems and leaves => 6
5b Flower buds swollen, unopened. I. sempervirens: Unidentified gall midge
6a Stem slightly stunted, with ± discoloured leaves, folded upwards, usually additionally curled. I. sempervirens: Brevicoryne brassicae
6b Glossy white, later on with mealy dusting, ± bulging swelling additionally usually slightly curved young axial parts or midribs of leaves. Also rotund dusty pads, in many Iberis species with violet-red margin, on yellowing leaf blades enclosed by a “chlorophyll isle”, on underside. I. amara, carnosa, “pruittii”, umbellata: Albugo candida
6c Upperside of the leaves with yellowish spots. Their underside with a white down, consisting of erect conidiophores that apically are dichotomously branching several times, each branch ending in a conidium. I. amara, gibraltarica, “pruitti”, saxatilis, sempervirens: Hyaloperonospora iberidis