Plant Parasites of Europe

leafminers, galls and fungi

gallers on Odontites

Dichotomous table for gallers on Odontites

(see also Euphrasia)

by Hans Roskam

1a On parts above ground => 2

1b Roots with small, nodular or spindle-shaped swellings. O. verna: Meloidogyne hapla

= Cysts of a Heterodera species may occur on this host

2a On vegetative parts => 3

2b Ovaries irregularly swollen, containing a yellow larva. O. verna: Unidentified gall midge

3a Single galls wart-shaped, caused by fungi fruiting inside the host cells => 6

3b Malformations more expanded => 4

4a Malformations caused by fungi, fruiting at surface or sporulating after rupturing of bulges => 5

4b Spindle-shaped or irregularly expanded, spongy, pale-green swellings on stems and leaf veins of plants which are severely stunted. Odontites spp.: Ditylenchus dipsaci

5a Systemically infected plants or shoots developing faster, rigidly erect. Leaves pale-green, narrowed, curved downwards at margin, arched; soon covered with a dense white down of branched conidiophores. O. litoralis, vulgaris: Plasmopara densa

5b Stem with thinner or thicker quill-like swellings, up to several cm long, blue-grey, at first closed, later on rupturing and dusty. Infestation sometimes as bulge-shaped sori encroaching onto leaves. O. lutea: Urocystis schizocaulon

6a Wart-shaped, multi-cellular galls on leaves and stems, less than 1 mm across, occasionally coalescing; nutritive cells with golden-yellow perennial sorus. O. verna: Synchytrium aureum

6b Complete plant disfigured. Shoot axis and leaves with rotund red warts, usually gregarious, up to 1 mm across. Perennial spores inside a single (rarely in 2–3) enlarged parenchyma cells. O. verna, vulgaris: Physoderma negeri

Last modified 22.v.2020