Dichotomous table for gallers on Laburnum
(incl. Laburnocytisus, Lembotropis)
by Hans Roskam
1a On parts above ground => 2
1b Oval to cylindrical, also hand-shaped to coralloid branched nodules, laterally attached to the roots; occasionally coalesced into larger clusters. Laburnum spp.: Rhizobium leguminosarum
2a On inflorescences or pods => 5
2b On vegetative organs => 3
3a On axial parts => 4
3b Buds swollen, walls of cavity inside lined with black mycelium. L. anagyroides: Asphondylia sp.
3c Leaves stunted, sometimes deflected over their top, margin ± curved downwards, leaf blade folded or curled. Laburnum alpinum, anagyroides, watereri; Lembotropis nigricans: Aphis cytisorum
4a Thicker branches with spindle- to club-shaped swellings bearing mistletoe. Laburnum spp.: Viscum album
4b Bark of young shoots with rimmed depressions, each containing a flat froth-covered nymph. Laburnum spp.: Chionaspis salicis
5a nflorescence variously disfigured. Laburnum anagyroides; Lembotropis nigricans: Aculops cytisicolus
5b Fruit with conspicuous swelling. Laburnum spp.: Inducer unknown