Microbotryum koenigiae (Rostr.) Vánky 1998

Ustilago koenigiae Rostr. Medd. Grenland 3 : 532. 1888
Sori on stems and sometimes on leaves, forming subspherical to linear pustules, upon rupture disclosing somewhat dusty purplish spore-mass ; spores very light-violet, irregular, oblong to spherical, apparently smooth but under an immersion lens showing very minute oblique striae, chiefly 6-9 /i, the most elongate rarely 12 /i, in length.
On Polygonaceae :
Macounastrum islandicum. {Koenigia islandica)^ Greenland. Type locality : Greenland, on Koenigia islandica {Macounastrum. islandicum.). Distribution : Known only from the type locality.