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).