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Family: PleosporaceaeGenus: Alternaria
Colonies in necrotic spots on leaves and bulb scales, forming a black granular mat of conidiophores over the entire infected area.
Anamorph: conidiomata absent. Conidiophores 4-6 µm diam., simple or irregularly branched, dark brown, septate, the fertile part slightly paler, elongate, irregularly geniculate and proliferating sympodially with conspicuous thickened black scars. Conidia (22-) 25-36 (-40.5) x (6.5-) 9.5-11 (-15.5) µm, irregularly catenate, olivaceous to blackish brown, ellipsoidal or ovoid to subcylindrical, the base rounded and the apex obtuse, slightly constricted at the 3-7 strongly thickened transverse septa and with one to three cells divided with an oblique to longitudinal septum, ± smooth, without a gelatinous sheath or appendages.