Plant Parasites of Europe

leafminers, galls and fungi

gallers on genus Linum

Dichotomous table for gallers on Linum

by Hans Roskam

1a On shoot parts => 2

1b Roots with nodular swellings. L. usatissimum: Meloidogyne hapla

2a On shoot tips or flowers => 4

2b On leaves or stems mainly of young plants => 3

3a Weak swellings bearing pale yellow spermogonia and orange aecia on cotyledons or young stems. Linum spp.: Melampsora liniperda

= On L. catharticum lives Melampsora lini

3b Young plants largely disfigured, excessively leafy, shoots thickened basally, sometimes ± curved. Leaves clustered, undulate, ± swollen and twisted. Occasionally localised, ± irregular, spongy, pale green swellings also on higher inserted, stunted stem parts and leaves of further developing plants. L. usitatissimum, tenuifolium: Ditylenchus dipsaci

4a On shoot tips or terminal shoots => 5

4b Greened flowers on ± stunted plants. L. catharticum: Unidentified gall mite

= The gall midge Contarinia lini is galling flower buds of L. austriacum

5a Terminal leaves widened, keel-like, making a larval chamber, about 8 x 4 mm long, containing a single larva. Neighbouring leaves ± disfigured and clustered, rosette-like. L. alpinum, austriacum, bienne, catharticum, tenuifolium, usitatissimum: Dasineura sampaina

5b Variously disfigured, pale leaves clustered on shoot tips of distorted plants. L. usitatissimum: Thrips linarius and/or Th. angusticeps

Last modified 18.xi.2023