Plant Parasites of Europe

leafminers, galls and fungi

gallers on Succisa

Dichotomous table for gallers on Succisa pratensis

by Hans Roskam

1a On parts above ground => 2

1b Roots usually with several to many nodular to spindle-shaped swellings, bearing several lateral roots. Meloidogyne hapla

2a In capitula or flowers => 4

2b On leaves => 3

3a Broad, many-celled warts, up to 1 mm high, pearl-like, yellowish-green. Usually many, solitary or variously coalesced later on into ± browned, flat ridges or crusts; after infestation on all green, not distinctly discoloured organs. Synchytrium succisae

3b Leaf blade with small grooves on underside. Mites free-living on underside of leaves, if strongly infected, conspicuously pale or brownish discoloured. Leipothrix succisae

4a Malformations caused by fungi => 5

4b Flowers compact, ± disfigured; unopened. Containing a whitish- to orange-yellow larva. Contarinia dipsacearum

5a Fungus develops on several flower parts or in ovary => 6

5b Fungus lives in externally unchanged flowers in originally shortened and bloated, soon completely aborted anthers; containing a whitish, to ochre coloured, later on dusty spore powder. Microbotryum succisae

5c The anthers are transformed into a purplish-brown powdery mass of spores.Microbotryum flosculorum

6a Diseased flowers sometimes strange-looking, ± discoloured. Several petals enlarged and ± disfigured. Generative parts greatly reduced. Loose down of branched conidiophores on emerging petals of usually completely diseased capitula. Peronospora violacea

6b Fungus develops in soon destroyed ovary, stigmas thickened and distorted; corolla unopened; anthers normal. Strongly infected capitula prematurely browned and dying. Covered with salmon-pink to orange slimy speckles when spores are mature. Gibberella fujikuroi

Last modified 20.vi.2020