Plant Parasites of Europe

leafminers, galls and fungi

Melanopsichium pennsylvanicum

Melanopsichium pennsylvanicum Hirschhorn, 1941

on Persicaria, Polygonum

Melanopsichium pennsylvanicum on Persicaria lapathifolia

Persicaria lapathifolia, Belgium, prov. Antwerp, Herselt, Varenbroek, 20.viii.20211 © Carina Van Steenwinkel: inflorescence with galled flower bud

Melanopsichium pennsylvanicum on Persicaria lapathifolia

detail

Melanopsichium pennsylvanicum on Persicaria lapathifolia

section through a gall

Melanopsichium pennsylvanicum on Persicaria lapathifolia

sporen

Melanopsichium pennsylvanicum on Persicaria lapathifolia

spores ± 7 x 10 µm

Melanopsichium pennsylvanicum on Persicaria lapathifolia

in indian ink it is clearly visible that the spores are covered by
layer of slime

Melanopsichium pennsylvanicum on Persicaria lapathifolia

2.x.20211, old, disintegrating gall

Melanopsichium pennsylvanicum on Persicaria lapathifolia

Persicaria lapathifolia, Zwartebroek, nr Vossenweg, 8.viii.2018 © Margreet Heslinga

Melanopsichium pennsylvanicum on Persicaria lapathifolia

detail

Melanopsichium pennsylvanicum on Persicaria lapathifolia

another specimen

Melanopsichium pennsylvanicum: spores

spores

Melanopsichium pennsylvanicum: spores

detail

gall

(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.

host plants

Polygonaceae, narrowly oligophagous

Persicaria hydropiper, lapathifolia, maculosa, minor; Polygonum arenastrum, aviculare.

synonyms

? 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.

references

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).

Last modified 17.iii.2022