Colletotrichum sonchicola Jayawardena, Camporesi & K.D. Hyde sp. nov., Index Fungorum number: IF 553182

Etymology: Refers to the host genus.

Saprobic on dead and aerial stem of Sonchus sp. Sexual morph : undetermined. Asexual morph: Conidiomata 240–415 μm ( = 320 μm, n = 10) diam., black, acervulus, oval, solitory, gregarious, comprising dark brown, roundish cells from which setae and conidiophores develop. Setae straight or ± bent, abundant, mostly occur as a group, dark brown to light brown, becoming paler towards the apex, light brown to opaque, smooth walled, septate, 1–3 septate, up to 110 μm long, base cylindrical, slightly inflated, 5.25 μm diam., apex acute to rounded. Chlamydospores not observed. Conidiophores simple, to 18 μm long, hyaline to pale brown, smooth-walled, Conidiogenous cells 12–17 × 2–3 μm ( = 14.5±3.4 × 2.6±0.4 μm, n = 20), hyaline, smooth–walled, cyllindrical to slighty inflated, opening 0.5–1 μm wide, collarette or periclinal thickening not observed. Conidia 17–23 × 2–3 μm ( = 20.2±1.9 × 2.5±0.6 μm, n = 40), L/W ratio 8.0, hyaline, smooth or verruculose, aseptate, very variable in size and shape; some strongly curved, more strongly curved towards the often broadly rounded apex than towards the truncate base, some small conidia almost straight, guttulate. Appressoria 9–17 ×2–6 μm ( = 11.5±3.2 × 3.6±1.4 μm, n = 10), L/W ratio 3.2, solitary or in loose groups, single celled, olivaceous brown to dark brown, irregularly shaped, but often with globose, clavate to somewhat triangular outline, strongly lobed when lobes are present, smooth walled.

Culture characteristics: Colonies on PDA flat with entire margin, aerial mycelium sparse, short, pale olivaceous-grey, iron-grey acervuli can be observed mainly on the edge of the colony. Reverse olivaceous green, reaching 60–75 mm in 7 d at 18 °C.

Type: ITALY. Province of Forlì-Cesena [FC]: Riofreddo—Bagno di Romagna, on dead and aerial stem of Sonchus sp. (Asteraceae), 2 October 2016, Erio Camporesi, (MFLU 16-2539, holotype), ex-type culture, (IT3115a) KUMCC 17-0132= MFLUCC 17-1299, ibid cultures MFLUCC17-1300, JZB330117.

Distribution: Riofreddo—Bagno di Romagna, Province of Forlì-Cesena [FC], ITALY.

FIG 2. Colletotrichum sonchicola (holotype). A–B. Appearance of conidiomata on host. C. Setae. D–F. Apex of setae. G. Conidiophores. H. Conidiogenous cells. I–K. Conidia. L–M. Appressoria. N. Upper view of 7 d old culture. O. Reverse view of 7 d old culture. Scale bars: A–B = 0.2 mm, C, G = 20 μm, D–F, H–M = 10 μm.