Arthrinium curvatum var. minus M.B. Ellis, Trans. Brit. Mycol. Soc. 34: 501 (1951)

Pintos, Angel, Alvarado, Pablo, Planas, Juan & Jarling, Rene, 2019, Six new species of Arthrinium from Europe and notes about A. caricicola and other species found in Carex spp. hosts, MycoKeys 49, pp. 15-48 : 15

Arthrinium curvatum var. minus M.B. Ellis, Trans. Brit. Mycol. Soc. 34: 501 (1951) Fig. 5

Physalospora scirpi Arx, Gen. Fungi Sporul. Cult. (Lehr): 116 (1970).

Pseudoguignardia scirpi Gutner, Mater. Mikol. Fitopat. Ross. 6(1): 311 (1927).

Description.

Asexual morph: Colonies are compact, round, dark to black, 80-320 in diameter. Mycelium is composed of hyaline to pale brown smooth hyphae 2-7 µm in diameter. Conidiophore mother cells spherical to lageniform, hyaline with brown pigments at the base, measuring (4 –)5–7(– 8) × (4 –)5–6(– 7) µm (n = 30). Conidiophores cylindrical unbranched, straight or flexuous, hyaline and smooth walled, with a single brown transversal septa, measuring 30-100 × 2-4 µm. (n = 30). Conidiogenous cells cylindrical 1-1.5 × 1-1.5 µm (n = 20). Conidia borne along the sides of conidiophores, curved, rounded at the ends, brown, with a hyaline germ slit and a clearly visible scar, (8 –)9–10(– 11) µm long in frontal view, (5 –)6–7(– 8) µm in side view (n = 30). Sterile cells rounded, paler than conidia. Culture characteristics flat colonies spreading on MEA 2% with moderate aerial mycelium, reverse withish.

Notes.

Arthrinium curvatum var. minus can be confused with A. curvatum var. curvatum , but conidia of var. minus measure (8 –)9–10(– 11) × (5 –)6–7(– 8) µm, while those of A. curvatum var. curvatum measure 11-15 × 6-8 µm. Gutner (1927) described Pseudoguignardia scirpi , a sexual morph of A. curvatum , later combined as Physalospora scirpi ( Arx 1970). Arthrinium curvatum var. minus is closely related with A. sporophleum (with lemon-shaped conidia) and A. japonicum (with larger fusiform conidia) and to a lesser extent also with A. caricicola (with larger fusiform conidia) and A. puccinioides (with polygonal conidia). Ellis et al. (1951) described A. curvatum var. minus , a taxon with similarly shaped but smaller conidia than A. curvatum . The specimen studied in the present work matches the shape and size of conidia reported by Ellis et al. (1951) for A. curvatum var. minus , rather than those of A. curvatum var. curvatum .

Specimens examined.

Germany: Brandenburg: south of Liberose, on dead leaves of Carex sp., 28 Mar. 2018, R. Jarling (MA-Fungi 91726).