Dichotomous table for gallers on Hyoscyamus
by Hans Roskam
1a Leaves rolled inwards and ± curled. H. aureus, niger: Aphis fabae
1b On roots and stems => 2
2a Galls only on roots, primarily on adventitious roots; caused by eelworms => 4
2b Galls on main roots, sometimes encroaching onto stem base or only on stems => 3
3a Many proliferations, 1–3 mm long, rotund or irregularly shaped, which develop from side-, or higher located adventitious roots. H. niger: Synchytrium endobioticum
3b Young plants stunted; the basal stem parts and leaves, occasionally also the veins of leaves inserted there are ± sponge-like swollen H. aureus, niger: Ditylenchus dipsaci
4a Roots, especially side roots, with ± distinctly separated, nodular or spindle-shaped swellings with many side roots. H. aureus, niger: Meloidogyne hapla
4b Roots with slightly protruding, elongated, irregular tuberculate swellings; the parts situated beyond infestation usually disfigured. The developing ♀ ruptures the root rind with its body, producing the at first white, then yellow, eventually brown cysts attached to the outside of the gall body. H. aureus, niger: Globodera rostochiensis