Dichotomous table for gallers on Minuartia
(incl. Honckenya. ‒ Comp. Arenaria, Stellaria)
by Hans Roskam
1a On stems and leaves => 3
1b On flowers => 2
2a Flowers ± swollen globularly, unopened. Inner organs soon destroyed and replaced by spore balls consisting of a yellowish-brown powdery dust. Arenaria pungens; Minuartia hybrida: Thecaphora saponariae s.l.
2b Flowers outwardly not conspicuously changed; anthers shortened and swollen; later on filled with a dusty violet spore powder. M. recurva: Microbotryum violaceum
3a Malformations caused by fungi fruiting at surface => 5
3b Malformations caused by animals => 4
4a Leaves on slightly stunted shoots more densely arranged, the leaf blades a little deflected over their tip, curved upwards at margin. Honckenia peploides: Myzus certus
4b Shoot axis stunted, bent at infestation site. Leaves more clustered, leaf blades distorted. Honckenia peploides: Philaenus spumarius
5a Leaves or stem with rotund- oblong-oval, yellowish brown pads, occasionally slightly bent, protruding on underside, soon bearing a brown sorus at surface. Arenaria montana, retusa, serpyllifolia, tenuifolia; Minuartia hybrida, laricifolia, verna: Puccinia arenariae
5b Systemic diseased shoots growing rigidly erect; leaves reduced, slightly thickened and ± bent, spoon-like. On leaf underside and stem grey down of conidiophores develop. Honckenia peploides: Peronospora honckenyae
5c Bushy accumulation on twisted and thickened stems; capsules inflated. M. viscosa: Inducer unknown