Sexual morph not observed. Asexual morph on SNA. Vegetative hyphae hyaline, smooth-walled, septate, branched, 1–6 μm diam. Chlamydospores not observed. Conidiomata absent, conidiophores formed directly on hyphae. Setae not observed. Conidiophores hyaline, smooth-walled, simple or septate and branched, up to 45 μm long. Conidiogenous cells hyaline, smooth-walled, cylindrical, conical or ± inflated, 5.5–18 × 2–3.5 μm, opening 1–1.5 μm diam, collarette 0.5–1.5, periclinal thickening visible. Conidia hyaline, smooth-walled, aseptate, straight, cylindrical to fusiform with one round and one truncate end, (11–)15.5–21(–22.5) × (3–)3.5–4(–4.5) μm, mean ± SD = 18.3 ± 2.9 × 3.8 ± 0.4 μm, L/W ratio = 4.9. Appressoria not observed. Asexual morph on Anthriscus stem. Conidiomata absent, conidiophores formed directly on hyphae. Setae not observed. Conidiophores, hyaline, smooth-walled, septate, sometimes branched, up to 50 μm long. Conidiogenous cells, hyaline, smooth-walled, cylindrical to clavate, 20–27 × 2.5–4 μm, opening 1–1.5 μm diam, collarette 1 μm, periclinal thickening visible. Conidia hyaline, smooth-walled, aseptate, straight, cylindrical to fusiform with one round and one truncate end, (n = 18) measure (15–)16–20.5(–23) × 3.5–4.5 μm, mean ± SD = 18.1 ± 2.3 × 4.0 ± 0.4 μm, L/W ratio = 4.6. Culture characteristics: Colonies on SNA flat with entire margin, hyaline, medium partly covert with very short white aerial mycelium, reverse same colours; 14.5–15.5 mm in 7 d (21–24 mm in 10 d). Colonies on OA flat with entire margin, white, pale olivaceous grey to greyish sepia, surface covert with thin, short floccose white aerial mycelium, reverse white to pale olivaceous grey; 11–16.5 mm in 7 d (16–24 mm in 10 d). Conidia in mass not observed.

Kinghorn (1936) worked on two strains isolated from Phormium from material collected in Scotland by N.L. Alcock. Both of these were identified as C. phormii by Farr et al. (2006). One of these is confirmed as C. phormii in this study, but we have found the other (CBS 198.35) to be distinct in molecular terms. Kinghorn named his material Glomerella phacidiomorpha, but Farr et al. (2006) examined the type of that name and found it to be a species of Phaeosphaeriopsis. Colletotrichum kinghornii is one of the two species in the C. acutatum complex with the largest conidia; only those of C. phormii are bigger. However, strain CBS 198.35 hardly sporulates, and the conidia measured were mostly formed in the aerial mycelium. According to the molecular analyses, strain CBS 198.35 must be considered separate at species rank from C. phormii, with several sequence differences in almost every gene, and a single bp difference in the ITS sequence (this was not detected in the Farr et al. study). Colletotrichum kinghornii is most effectively separated from other species using HIS3.

UK, Scotland, from Phormium tenax, unknown collection date, N.L. Alcock (deposited in CBS collection Feb. 1935 by W.O. Kinghorn as Glomerella phacidiomorpha), (CBS H-20909 holotype, culture ex-type CBS 198.35).

Sexual morph not observed. Asexual morph on SNA. Vegetative hyphae 1–5 μm diam, hyaline, smooth-walled, septate, branched. Chlamydospores not observed. Conidiomata absent, conidiophores formed directly on hyphae. Setae not observed. Conidiophores hyaline to very pale brown, smooth-walled to finely verruculose, simple or septate and branched, to 40 μm in length. Conidiogenous cells hyaline to pale brown, smooth-walled to finely verruculose, cylindrical, elongate ampulliform to ampulliform, 7.5–16.5 × 2.2–4.5 μm, opening 1–1.5 μm diam, collarette 1–2 μm long, periclinal thickening visible. Conidia hyaline, smooth-walled or verruculose, aseptate, straight, cylindrical to fusiform with both ends acute or one end round and one end acute, (17–)20–26(–35.5) × 4–5(–6.5) μm, mean ± SD = 23.0 ± 3.2 × 4.6 ± 0.6 μm, L/W ratio = 5.1. Appressoria single or in loose groups, medium to dark brown, outline mostly oblong to irregular, the edge entire or undulate, rarely lobate, (4–)8.5–20.5(–32) × (2.5–)4–6(–8) μm, mean ± SD = 14.5 ± 6.2 × 5.1 ± 1.0 μm, L/W ratio = 2.9, appressoria of strain CBS 102054 are shorter, measuring (5.5–)8–13(–14.5) × 5–6.5(–8) μm, mean ± SD = 10.4 ± 2.4 × 5.8 ± 0.8 μm, L/W ratio = 1.8. Asexual morph on Anthriscus stem. Conidiomata acervular, conidiophores and setae formed on a cushion of pale brown roundish to angular cells, 2.5–10 μm diam. Setae few, hyaline to medium brown, smooth-walled, 0–1-septate, 25–70 μm long, base cylindrical, to 5 μm diam, tip ± roundish to ± acute. Conidiophores pale brown, smooth-walled, septate, branched, to 50 μm long. Conidiogenous cells pale brown, smooth-walled, usually cylindrical, sometimes elongate ampulliform to ampulliform, 8–25 × 2.5–3.5(–5.5) μm, opening 1–1.5 μm diam, collarette 1 μm long, periclinal thickening visible. Conidia hyaline, smooth-walled, aseptate, straight, cylindrical to fusiform with both ends acute, (14–)20–24.5(–25.5) × 4–4.5(–5) μm (one conidium measured 47 × 5 μm), mean ± SD = 22.3 ± 2.3 × 4.3 ± 0.2 μm, L/W ratio = 5.2, conidia of most other strains are slightly broader and those of strain CBS 118191 are additionally shorter than conidia of the ex-epitype strain, measuring (14–)18.5–22(–24) × (4–)4.5–5(–5.5) μm, mean ± SD = 20.3 ± 1.9 × 4.9 ± 0.4 μm, L/W ratio = 4.1. Culture characteristics: Colonies on SNA flat with entire margin, hyaline with felty white aerial mycelium on Anthriscus stem and filter paper, filter paper on both sides partially olivaceous to pale olivaceous grey; growth rate 15–19 mm in 7 d (27.5–32.5 mm in 10 d). Colonies on OA flat with entire margin; surface buff, with olivaceous to grey olivaceous sectors, and roundish olivaceous grey structures embedded in the medium, surface partly covered with floccose-felty white to pale olivaceous grey aerial mycelium, reverse buff with pale to dark olivaceous grey sectors; growth rate 15–21 mm in 7 d (27.5–33.5 mm in 10 d). Conidia in mass salmon.

The synonymy given for this species follows Farr et al. (2006), and this work should be consulted for details. Fusarium phormii was described by Hennings (1898) on leaves of Phormium tenax in the Botanical Garden in Berlin, Germany, as forming sporodochia with oblong-cylindrical to fusoid, straight to slightly curved, multiguttulate, hyaline conidia, measuring 18–25 × 4–6 μm. Hennings (1898) found this fungus together with Physalospora phormii, and assumed the two belonged together. Fusarium phormii is formed on the leaf surface, while the perithecia of P. phormii appear on the undersurface. Kinghorn (1936) observed structures considered to be the sexual morph of C. phormii on leaves of Phormium plants but not in culture, as did von Arx (in litt.). We have found, however, that Kinghorn was looking at two species; part of this material belongs to a species that is named in the present publication as C. kinghornii. The sexual morph, originally named as Physalospora phormii, was originally found by Schröter (1894) on dead leaves of Phormium tenax in Breslau, Germany (today: Wrocław, Poland).