Plant Parasites of Europe

leafminers, galls and fungi

gallers on Valerianella

Dichotomous table for gallers on Valerianella

by Hans Roskam

1a On leaves, stems or/and inflorescences => 2

= As causer of root galls on V. locusta has been recorded the Root knot eelworm Meloidogyne hapla

1b Ovary swollen, up to 7 mm long, disfigured. Containing a single white larva. V. carinata, dentata, locusta, rimosa: Cecconia valerianellae

2a Malformations on vegetative organs, sometimes encroaching onto inflorescence primordia => 3

2b Many flowers in an inflorescence conspicuously disfigured. Corolla greatly enlarged, transformed into a lobed, succulent annular disc. Stamens corolla-like. Valerianella sp.: Unidentified gall mite

3a Malformations caused by fungi fruiting on outside => 5

3b Malformations caused by animals => 4

4a Young plants severely stunted. Leaves from basal part upwards variously spongy swollen, the higher situated parts ± disfigured. Stem primordia similarly thickened. V. dentata, locusta: Ditylenchus dipsaci

4b Leaves widened and shortened, ± distorted or rolled. Inflorescence axis shortened. Flowers clustered into rotund, pale green balls. Calyx enlarged, often deeply incised. Tips almost leaf-like, greened or leafy. Stamens aborted. Bracts folded and distorted. V. carinata, coronata, dentata, locusta, rimosa: Trioza centranthi

5a Fungi in expanded, not distinctly restricted malformations => 6

5b Plants usually infected systemically and often not reaching the flowering stage. Organs variously disfigured. Sori on leaf underside, or on all sides of axial parts with ± uniformly arranged whitish aecia. V. carinata, dentata, locusta, rimosa: Puccinia gladioli

6a Plants largely or completely covered by a loose, dusty mycelium. Infected parts variously ± disfigured or often not gall-like V. carinata, dentata, eriocarpa, locusta, rimosa: Golovinomyces orontii

6b On various Erysiphaceae [powdery mildews] develops the widely distributed and rather frequent Ampelomyces quisqualis

6c Systemically infected shoots pale green, on axial parts weakly hypertrophied; leaves slightly thickened, leaf blades ± stunted, margins slightly deflected, with a down of dirty white, branched conidiophores on underside. V. carinata, dentata, discoidea, locusta, rimosa: Peronospora valerianellae

6d Leaves and stem, usually with many, minute greenish to brown globular warts. V. locusta: Synchytrium valerianellae

Last modified 12.v.2020