Melanustilospora ari (Cooke) Denchev, 2003

on Arum

parasite

Relatively extensive, ill-delimited, greyish green leaf spots, not delimited by veins. The infection is inconspicuous, the leaf surface is only lightly swollen. Embedded in the leaf tissue lie masses of roundish, yellow-brown spores with a smooth, double wall of uneven thickness, 13-17 µm in diameter.

hostplants

Araceae, oligophagous

Arum besserianum, cylindraceum, elongatum, italicum, maculatum, orientale subsp. danicum; Biarum tenuifolium.

synonyms

Melanotaenium ari.

notes

The description above is based on photos in the website of Julia Kruse (Pflanzenbestimmung). Carina Van Steenwinkel has studied plants with blackish swollen spots like in the pictures below, and found that these spots have nothing to do with the fungus and probably are not pathological at all.