Arthrinium caricicola Kunze & J.C. Schmidt, Mykologische Hefte (Leipzig) 1: 9 (1817)

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 caricicola Kunze & J.C. Schmidt, Mykologische Hefte (Leipzig) 1: 9 (1817) Fig. 4

Description.

Asexual morph: colonies on the host punctiform, pulvinate, 140-400 µm in diameter, blackish brown. Mycelium formed by hyaline smooth, branched hyphae, 2-5 µm in diameter. Conidiophore mother cells arising from a superficial or erumpent mycelial mat, subspherical to lageniform in shape, hyaline with brown pigments at the base, measuring (4 –)5–7(– 8) × (8 –)9–11(– 12) µm (n = 45). Conidiophores erect or ascending, simple, straight or flexuous, cylindrical, smooth-walled, colourless excepting for the thick, brown to dark brown, transversal septa, 15-100 × 3-5 µm (n = 50). Conidia fusiform or broadly spindle-shaped, smooth-walled, broader at the middle, tapering towards the narrowly rounded ends, dark brown with a hyaline rim, (37 –)44–51(– 55) µm in frontal view, (8 –)9–11(– 12) µm in side view (n = 50). Sterile cells smaller, 15-19 × 10-13 µm, and paler than conidia, bicuspidate or irregularly lobed. Culture characteristics: flat colonies spreading on MEA 2%, with moderately abundant, white cottony aerial mycelium, reverse whitish too, circular in shape with irregular edge.

Notes.

The conidia of A. caricicola and A. japonicum have a similar fusiform shape and length, but differ in width ((8 –)9–11(– 12) µm vs 12 –16(– 20) µm). Conidia of A. mytilimorphum have also a similar shape, but turns out shorter and thinner (20-30 × 6-8.5 µm). The morphological characters of the syntype of A. caricicola deposited by Fries in the Herbarium of Uppsala University as Fung. Scleromyc. Suecici, fully match the specimen collected in this study. The closely related species A. sporophleum has very different lemon-shaped conidia, while those of A. curvatum var. minus are curved, and those of A. puccinioides are polygonal.

Specimens examined.

Germany: Brandenburg: south of Liberose, on dead leaves of Carex ericetorum , 14 May 2018, R. Jarling (MA-Fungi 91725).