Ustilago avenae (Persoon) Rostrup, 1890
loose smut of oats
on oat, etc.
Arrhenatherum elatius, Nieuwendam
detail
galled spikelet
same plant, somewhat less than a year later (the fungus is systemic): earlier stage of the infestation
Arrhenatherum elatius, Nieuwendam; whether the reduction of the awns is connected with the infection is not clear
all ovaries are black and swollen
the fungus erupts through the glumes
seen from the side
ten days later; the glumes are intact, within them the destruction is complete
spores
gall
The fungus primarily affects the ovaries, to a lesser degrees also the other parts of the spikelet. Spores c. 6 µm, olive brown when ripe; then also one can see that the spores are lighter at one side; wall spinulose. The infection begins at the seedlings.
host plants
Poaceae, oligophagous
Aegilops cylindrica, triuncialis; Arrhenatherum elatius; Avena barbata, fatua, nuda, sativa, sterilis & subsp. ludoviciana, strigosa; Dasypyrum villosum; Hordeum, murinum, vulgare & ? subsp. distichon.
synonyms
Ustilago arrhenatheri Schellenberg, 1915; U. aegiliopsidis Picbauer, 1932; U. decipiens (Wallroth) Liro, 1924; U. haynaldiae Becerescu, 1970; U. levis (Kellerman & Swingle) Magnus; U. nigra Tapke, 1932; U. perennans Rostrup, 1890; U. rostrupii Kutinen, 1922; U. segetum var. avenae (Persoon) Brunaud, 1878.
In her recent book, Kruse (2019a) treats Ustilago perennans as a valid species, parasitising Arrhenatherum elatius.
references
Ainsworth & Sampson (1950a), Almaraz (1998a), Beltran Tejera (1976a), Brandenburger (1985a: 779, 808), Buhr (1964b), Doppelbaur (1973a), Ellis & Ellis (1997a), Ivić, Sever, Scheuer & Lutz (2013a), Jage, Klenke, Kruse ao (2016a), Jage, Kruse, Kummer ao (2013a), Kabaktepe & Akata (2019a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2019a), Llorens i Villagrasa (1984a), Losa España (1944a), Lutz & Vánky (2009a), Melgarejo Nárdiz, García-Jiménez, Jordá Gutiérrez ao (2010a), Navarro, Honrubia & Torres (1986a), Nielsen & Huang (1984a), Prillinger, Wuczkowski, Lopandic ao (2009a), Savchenko & Heluta (2012a), Scheuer & Bechter (2012a), Scholz & Scholz (2013a), Tomala-Bednarek (1977a), Tomasi (2014a), Unamuno (1941b, 1942a), Vanderweyen & Fraiture (2014a), Vánky (1994a, 2012a), Vánky & Abbasi (2013a), Woods, Chater, Smith ao (2018a), Zwetko (1993a).