Plant Parasites of Europe

leafminers, galls and fungi

gallers on Oxalis

Dichotomous table for gallers on Oxalis

by Hans Roskam

1a On parts above ground => 2

1b Roots with nodular swellings. O. stricta: Meloidogyne hapla

2a On vegetative organs => 4

2b On flowers and fruits => 3

3a Flowers greened, ovaries elongated. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

3b Anthers and ovaries slightly swollen, later on containing reddish-brown spores. Diseased capsules sterile. Infestation not distinct before dusting of spores. O. fontana, stricta; not on O. corniculata: Thecaphora oxalidis

4a Malformations extended over several organs => 6

4b Galls localised => 5

5a Less than 1 mm long, sometimes joined, yellow many-celled warts on basal leaf- and stem parts. O. stricta: Synchytrium aureum

5b Slightly thickened cushions on leaves and petioles, with distinctly arched, cup-shaped aecia. ~, in NW-Eu on O. corniculata, fontana, stricta: Puccinia sorghi

6a Leaflets stunted, shorter stalked. Leaf blade rolled inwards, ± folded and twisted, finely wrinkled. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

6b Plant stunted, variously disfigured. Oxalis spp.: Aphis fabae

Last modified 22.v.2020