Plant Parasites of Europe

leafminers, galls and fungi

gallers on Alchemilla

Dichotomous table for gallers on Alchemilla

by Hans Roskam

1a Leaves remarkably long stalked, more erect, their leaf blades smaller, ± pale green, with orange-yellow to -red, often crowded fungal sori on the underside => 8

1b Malformations on leaf blades or -stalks without conspicuously coloured sori => 2

2a Malformations on leaf blades caused by aphids or spittlebugs => 7

2b Other causes => 3

3a On leaf blades => 4

3b Petiole thickened. A. vulgaris: Planchonia arabidis

4a Leaf blade folded, twisted, or with minor bulge-like swellings => 5

4b Leaf blade crumpled. Infestation sites sometimes conspicuously yellowish to reddish. With single or gregarious froth-covered nymphs on underside with black margined and castellated scale surrounded by a white margin of wax. A. alpina, glabra, pratensis, vulgaris: Bactericera femoralis

5a Leaf blade folded or twisted => 6

5b Leaf blade with slightly bulge-like, ± discoloured swellings, depressions on the underside of whitish covers of sori with branched conidiophores. Alchemilla spp.: Peronospora alchemillae

6a Leaf blade irregularly folded, here and there on underside with flat, rotund depressions, not abnormally pubescent. A. vulgaris: Unidentified gall mite

6b Leaf blade variously twisted, yellowish spotted. A. fissa: Unidentified gall mite

6c Minor swellings on ± stunted leaves. A. glomerulans, murbeckiana, xanthochlora: Calepitrimerus alchemillae

7a Leaf blade acutely bent downwards over large part; crumpled and dark green close to the froth-covered nymph. Alchemilla spp.: Philaenus spumarius

7b Leaf blade strongly curled; colonies of aphids on undersides. Alchemilla spp.: Aulacorthum solani

8a Underside often completely occupied with rotund or oblong, soon coalescing, orange-yellow to red lead sporangia. Alchemilla spp.: Trachyspora alchemillae

8b Similar malformations on A. alpigena, alpina, hoppeana, indivisa, nitida, velebitica: Trachyspora melospora

8c Very close to this fungus is a species occurring with expanded mycelium on hypertrophied chlorotic shoots of A. pentaphylla, with similar biology: Trachyspora pentaphylleae

Last modified 29.iv.2020