Dichotomous table for gallers on Lunaria
by Hans Roskam
1a On parts above ground => 3
1b On roots or root collar => 2
2a Irregular cylindrical, usually swelling on all sides, of variable length, on side roots and younger parts of main root. L. annua, rediviva: Plasmodiophora brassicae
2b Globular galls on root collar, with central larval chamber. L. annua, rediviva: Ceutorhynchus assimilis
3a On flowers or fruits => 9
3b On vegetative parts => 4
4a Malformations caused by animals => 6
4b Malformations caused by fungi => 5
5a Sori at first closed, glossy, porcelain-like, the conidia later develop on basal conidiophores in rows on rupturing, dusty pads. L. annua, rediviva: Albugo candida
5b Sori dull, conidia on branched conidiophores. L. annua, rediviva: Hyaloperonospora lunariae
6a Malformations caused by external plant feeders, aphids or spittlebugs => 8
6b Causers inside malformations; larvae of weevils => 7
7a Up to about 15 mm long, rotund to flattened spindle-shaped galls, also deep green inside with central larval chamber, on midrib, also petioles; occasionally on younger stem parts. Containing a single larva. L. annua: Ceutorhynchus chalybaeus
7b The shorter petioles of higher leaves as well as the lower part of the midrib are ± conspicuously deflected; inside are translucent, dark feeding tunnels, with wall cells often regenerating, causing swelling of the organs and sometimes even rupture. Containing a single beetle larva. L. annua: Ceutorhynchus pallidactylus
8a Leaf blades rolled- or deflected, almost nest-like. On main venation close to the froth-covered nymph curled and darker green than the parts towards leaf blade margin. L. annua, rediviva: Philaenus spumarius
8b Malformation of several, incompletely unfolded leaves on shoot tips, caused by mealy powdered grey-green aphids. L. annua, rediviva: Brevicoryne brassicae
9a Flowers thickened, unopened. L. annua: Contarinia nasturtii
9b Siliques severely disfigured, slightly discoloured, warty and bulging; seeds aborted. L. annua: Brevicoryne brassicae