Colletotrichum epimedii K. Y. Jiang & Zhong Li, 2025

Colletotrichum epimedii K. Y. Jiang & Zhong Li sp. nov.

Fig. 5 View Figure 5

Etymology.

Named after the host plant genus, Epimedium .

Type.

China • Guizhou Province, Kaili City, Bibao Town (26°30'38"N, 107°37'23"E), from leaves of E. sagittatum , Apr 12, 2024, KY Jiang (holotype HGUP 21489 , ex- - holotype culture GUCC 24-0190 ) GoogleMaps .

Description.

Sexual morph: Not observed. Asexual morph: Conidiomata, globose to irregular, ash black. Setae and conidiophores formed on a cushion of dark brown and are non-branched. Setae medium to dark brown, straight, 81.2–168.5 μm long, 1–2 septate, tip acut. Conidiophores hyaline, unbranched, upon maturation of the conidia, the apical portion undergoes constriction to form an ampulla or bowling pin-shaped structure, followed by subsequent detachment of the developed conidium. Conidia rough, non-septate, crescent or slightly curved in shape, with a near 1 / 2 mid-section having a depressed shape or multiple depressions, more towards the round or somewhat acute apex, base truncate, 16.5–18.8 × 4.3–5.4 μm (mean ± SD = 17.9 ± 0.8 × 4.7 ± 0.3 µm, L / W = 3.9). Appressoria single, grey – brown, irregularly shaped, 5.0–8.2 × 3.4–5.4 μm (mean ± SD = 6.1 ± 1.0 × 4.4 ± 0.4 µm, L / W = 1.4).

Culture characteristics.

Colonies on PDA taupe, rapidly growing to 8 cm within 7 days at 28 ° C, with a dense mycelium, covered by a velvety grey – brown aerial mycelium on the surface. The reverse side of the colony is black in the centre, gradually lightening towards the edge and fading to grey.

Notes.

Multi-locus phylogenetic analysis indicates that the three C. epimedii strains form distinct branches; our taxonomic unit C. epimedii belongs to the Spaethianum complex. It shares low sequence similarity with the phylogenetically related species C. incanum at act (96 %), chs- 1 (98 %), gapdh (92 %), his 3 (94 %), tub 2 (98 %) and ITS (99 %). Morphologically, C. epimedii and C. incanum had different colony characteristics on PDA. The C. incanum colony has fewer mycelia, growing closely against the plate, whereas C. epimedii has a dense mycelium. Both strains are dark brown but had different conidia sizes: C. epimedii had shorter but wider conidia than C. incanum , length (16.5–18.8 μm vs. 17.0–21.9 μm), width (4.3–5.4 μm vs. 2.3–3.7 μm) and L / W ratio (3.9 vs. 6.5). The setae of C. epimedii were also slightly shorter than those of C. incanum (81.2–168.4 μm vs. 74–202 μm) ( Yang et al. 2014). Considering both molecular phylogenetics and morphological characteristics, C. epimedii was identified as a new species.