Plant Parasites of Europe

leafminers, galls and fungi

gallers on genus Holosteum

Dichotomous table for gallers on Holosteum umbellatum

by Hans Roskam

1a Malformations on shoot axis or leaves => 2

1b Malformations of capsules or exceptionally on stems, containing black-violet spores; seed capsule not- or slightly disfigured; ovaries temporarily swollen, soon transformed into a black-violet spore mass. Microbotryum holostei

2a Malformations at the surface, with fruiting bodies of fungi => 3

2b Shoot axis thickened because of short- to oblong-oval swellings; a rimmed depression containing the causer. Planchonia arabidis

3a Brown, pad-shaped swollen telia; rotund on leaf underside, sometimes slightly countersunk on upper side, oblong-oval on axial parts, often resulting in distortions. Puccinia arenariae

3b More strongly infected plants are occasionally ± stunted and excessively leafy. Weaker systemic infestation results in development acceleration, associated with etiolation. On leaf underside of similarly disfigured shoots whitish-grey down of conidiophores develop. Peronospora holostei

Last modified 18.xi.2023