Codinaea lignicola (Z.L. Luo, H.Y. Su & K.D. Hyde) Réblová & Hern.-Restr., Journal of Fungi 7(12, no. 1097): 39 (2021)

MycoBank number: MB 842194; Index Fungorum number: IF 842194; Facesoffungi number: FoF 12808; Fig. 60

Basionym: Dictyochaeta lignicola Z.L. Luo, H.Y. Su & K.D. Hyde, Fungal Diversity 99: 595 (2019)

Saprobic on decaying submerged wood in freshwater. Asexual morph: Colonies effuse, hairy, scattered, or aggregated, brown, with white glistening conidial masses at the apex. Mycelium mostly immersed, composed of septate, smooth, thin-walled, mid-brown to pale brown hyphae. Setae fertile, erect, single, straight, or slightly flexuous, cylindrical, slightly tapering towards the apex, smooth, septate, thick-walled, dark brown at the base, paler towards the apex, 180–350 μm ( =270 μm, n = 20) long, 6–12 μm ( =8.3 μm, n = 20) wide near the base, 3–5 μm ( =3.9 μm, n = 20) wide at the apex. Conidiophores macronematous, mononematous, erect, straight, or slightly flexuous, cylindrical, smooth, 3–7-septate, unbranched, mid brown at the base, pale brown to hyaline towards the apex, paler than setae, arising in groups (2–6 conidiophores) from the mycelial knots from the bases of fertile setae, (50–)70–157(–217) × 3–5 µm ( = 105 × 3.8 µm, n = 40). Conidiogenous cells mostly polyphialidic, sometimes monophialidic, integrated, sometimes percurrently proliferating, terminal becoming intercalary, determinate, pale brown to hyaline, with up to 6 funnel-shaped collarettes. Conidia acropleurogenous, aggregated in slimy masses at the apex of conidiophores and setae, allantoid to lunate, aseptate, smooth, guttulate, hyaline, (10.9–)13–15.5(–17.2) × 2.2–3.9 µm ( = 14.7 × 3.2 µm, n = 30), thin-walled, with 3–8.5 μm long filiform appendages at both ends. Sexual morph: Undetermined.

Cultural characteristics – Conidia germinating on PDA medium within 24 h and germ tubes produced from one or both ends. Colonies on MEA medium reaching 5–10 mm diam. in a week at 25 °C, in natural light, circular, with velvety, dense, pale-yellow mycelium on the surface, sparser and pale brown at the entire margin; in reverse brown and dark brown.

Material examined – CHINA, Guizhou Province, Dushan District, 25.965° N, 107.65° E, on decaying wood submerged in a freshwater stream, 6 July 2018, J. Yang, SGT32-1 (HKAS 112577), living cultures MFLUCC 19-0274 and GZCC 20-0454.

Notes – Based on the phylogenetic analysis (Fig. 58), the LSU and ITS sequences of our isolate are identical to the holotype of Codinaea lignicola (DLUCC 0899). However, their morphology are different. The holotype is characterized by mononematous conidiophores and monophialidic or rarely polyphialidic conidiogenous cells without a seta (Luo et al. 2019). However, our collection often has 2–6 conidiophores in groups with a fertile, central seta and polyphialidic, terminal and intercalary conidiogenous cells. Conidiophores of the holotype are longer than that in our collection (204–276 µm vs. 50–217 µm) but shorter than setae (204–276 µm vs. 180–350 μm). Conidia in the holotype are shorter but broader than that in our collection (13–15 × 4.5–5.5 μm vs. 11–17 × 2–4 μm). Both collections were collected from freshwater streams in China. The presence or absence of setae and mono- or polyphialidic conidiogenous cells show less taxonomic value in their identification.

Figure 1. Codinaea lignicola (HKAS 112577). ab Colony on wood. cd Conidiogenous cells. ef Conidiophores, fertile setae and conidiogenous cells. gj Conidia. k Germinated conidium. lm Culture, l from above, m from below. Scale bars: ef = 50 μm, k = 20 μm, cd = 15 μm, gj = 10 μm