gallers on Aegopodium

1a On inflorescences, flowers or fruits => 9

1b On stems and leaves => 2

2a Leaf blades folded, curled, rolled inwards or with flat, ± bumpy swellings => 5

2b Leaves or stems with wart- to bulge-shaped galls => 3

3a Bulges over 1 mm long => 4

3b Galls wart-shaped, multi-cellular, less than 1 mm long, yellowish translucent; usually many on the underside of leaf blades, on petioles and basal stem parts; sometimes ridge- or crust-shaped coalescing: Synchytrium aureum

3c In similar galls: Physoderma pulposum

4a Spindle-shaped, compact, vitreous, pale green, later on ± browned bulges, often many on petioles, leaf veins and stems. Spores inside close to vascular bundle: Protomyces macrosporus

4b Leaves especially on underside, particularly on veins and stalks, with thickened, at first yellowish pads or bulges, on which develop 2-celled telia in black-brown sori, soon coalescing: Puccinia aegopodii

5a Leaf blades folded or flat to ± swollen, bulge-shaped => 7

5b Leaf blades rolled inwards or curled, caused by aphids or cercopids => 6

6a Leaf blades strongly converged downwards, almost claw-like; conspicuously curled and deeper green, especially close to the froth-covered nymph. Infected inflorescences stunted, compact: Philaenus spumarius

6b Tips of leaves usually transversely ± narrow to claw-like deflected downwards, irregularly shaped at surface on upper side by smaller or larger, often yellowish discoloured proliferations. Black aphids on underside: Aphis podagrariae

6c Aphid straw-pale to greenish: Aulacorthum aegopodii

7a Leaf blades with expanded swellings => 8

7b Tips of developing leaves folded upwards; ± curled and clumped. Main- and lower parts of lateral veins thickened. White larvae between folds: Macrolabis podagrariae

8a Often several upward protrusions of the leaf blade up to 6 mm long, hardly discoloured, sometimes violet marbled; corresponding depressions on opposite side; each groove contains an egg or larva: Trioza flavipennis

8b Leaves on underside with expanded white, loose covers of branched conidiophores. Infestation sites on upper side discoloured yellow-green, fast growing leaves sometimes slightly arched: Plasmopara crustosa

9a Galls only on flowers or fruits => 11

9b Umbel largely disfigured => 10

10a Development of umbel stunted, partial umbels accumulated because of shortened stalks. Flowers ± greened to leafy, often discoloured reddish: Unidentified gall mite

10b Partial umbels disfigured, clustered, stalks shortened, bearing green aphids: Cavariella aegopodii

11a lowers swollen, globular, not opening. Containing a single larva: Unidentified gall midge

11b Fruit distinctly swollen, bladder-like, protruding above the partial umbel. Containing an orange-red larva: Kiefferia pericarpiicola