Synchytrium anemones (de Candolle) Woronin, 1868

on Anemone, Pulsatilla

Anemone nemorosa, Belgium, prov. Flemish Brabant, Londerzeel, Drietorens, 19.iv.2021 © Eric Daelemans

underside of an infected leaf

the leaves may become severely disfigured

nevertheless the plants become in flower

even though the flowers themselves are infected

the sori are hard and smooth, not powdery

Anemone nemorosa, Belgium, prov. Flemish Brabant, Holsbeek, Dunbergbroek, 23.iv.2021 © Carina Van Steenwinkel

the galling of the floral parts demonstrates the high speed of the development of the galling

each tiny gall involves a central cell surrounded by a circle of accessory cells

detail, lighted from behind

optical section

picture of the oldest galled part of the plant

sometimes the central cell bears a prolongation

detail

possibly this applies to cells programmed to differentiate into a trichome

section through two central cells, in which a resting spore differentiates

detail

in the cell at right the resting spore has developed a resistant wall

gall

hard, red to black-violet warts, up to 0.5 mm large, mainly at the underside of the leaves.

host plants

Ranunculaceae, monophagous

Anemone coronaria, nemorosa, ranunculoides, “seemenii”, sylvestris; Pulsatilla alpina.

references

Buhr (1964b), Dauphin & Aniotsbehere (1997a), Dietrich (2013a), Karling (1964a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2019a), Redfern & Shirley (2011a), Tomasi (2014a).