Melanopsichium pennsylvanicum Hirschhorn, 1941
on Persicaria, Polygonum
Persicaria lapathifolia, Belgium, prov. Antwerp, Herselt, Varenbroek, 20.viii.20211 © Carina Van Steenwinkel: inflorescence with galled flower bud
section through a gall
spores ± 7 x 10 µm
in indian ink it is clearly visible that the spores are covered by
layer of slime
2.x.20211, old, disintegrating gall
Persicaria lapathifolia, Zwartebroek, nr Vossenweg, 8.viii.2018 © Margreet Heslinga
(part of) the inflorescence, sometimes also a part of the stem or a leaf is transformed into a black, lobed, in fresh condition elastic and viscid gall. The gall consists of hypertrophied plant tissue containing numerous chambers filled with spores embedded in a gelatinous matrix.
Polygonaceae, narrowly oligophagous
? Melanopsichium nepalense (Liro) Zundel, 1953: Spooner (1968a).
All European material that was identified as M. austro-americanum (Spegazzini) Beck, 1894 turned out to be pennsylvanicum (Vánky).
Vánky (1994a) provides images of the spores of both species, and the material from Zwartebroek shown above does not really match with either of them. The spores of Vánky’s pennsylvanicum have a clearly reticulated surface pattern, while the spores of austro-americanum are completely smooth under the light microscope. The identification of this material therefore can only be provisional.
Brandenburger (1985a: 87), Halisky & Barbe (1962a), Klenke & Scholler (2015a), McTaggart, Shivas, Geering ao (2002a), Mułenko, Piątek, Wołczańska ao (2010a), Redfern & Shirley (2011a), Negrean & Anastasiu (2006a), Prillinger, Wuczkowski, Lopandic, Bauer, MolnáO & Sterflinger (2009a), Savchenko & Heluta (2012a), Spooner (1986a), Van Steenwinkel, Fraiture & Vanderweyen (2022a), Vánky (1994a), Vánky, Vánky & Denchev (2011a), Vánky, Lutz & Bauer (2008b).