Dichotomous table for gallers on Scleranthus
by Hans Roskam
1a On parts above ground => 2
1b Roots with small, spindle-shaped swellings, bearing some side roots. S. annuus: Meloidogyne hapla
2a Malformations bearing fruiting bodies of fungi => 4
2b Malformations caused by animals => 3
3a Many leaves mainly distorted at shoot tips, thickened, sometimes bent S-shaped or rectangular, ± discoloured and showing suction feeding marks. S. annuus: Taeniothrips atratus
3b Whole plant atrophied. Basal parts with ± distinct, pale-green, spongy, soon necrotic, swellings. S. annuus: Ditylenchus dipsaci
4a Developing more on leaves if plants are infected early. Diseased shoots developing prematurely, growing rigidly erect. Internodes elongated, lanky; leaves smaller, slightly thickened, paler and often more deflected than healthy ones. Infected organs soon covered by a down of branched conidiophores. S. annuus, perennis: Peronospora scleranthi
4b Leaves and stems with rotund to oval powdery sori, sometimes slightly swollen and distorted on young organs, pale to red-brown. S. perennis: Uromyces scleranthi