Urocystis junci Lagerheim, 1888
on Juncus
gall
the interior of the culm is, over a length of up to 15 cm, modified into a blackish brown, powdery-granular mass of spore balls that are released when the, often spiralled, culm ruptures lengthwise.
hostplants
Juncaceae, monophagous
Juncus acutiflorus, acutus, arcticus, balticus, biglumis, filiformis.
references
Ainsworth & Sampson (1950a), Buhr (1964b), Klenke & Scholler (2015a), Lotze-Engelhard (2010a), Redfern & Shirley (2011a), Scholz & Scholz (2013a), Vánky (1994a), Wennström & Hagner (1999a).