Chaetothyrium guaraniticum Speg. [as ‘guaranticum’], Anal. Soc. cient. argent. 26(1): 46 (1888), Figure 2
MycoBank number: MB 241089; Index Fungorum number: IF 241089; Facesoffungi number: FoF 10325;
Saprobic on Aegle marmelos. Sexual morph: Ascomata 95–185 μm high × 80–110 μm diam. (x̅ = 111 × 90 μm, n = 10), perithecial, solitary, scattered, superficial, subglobose to circular, brown to dark brown, lacking an ostiole or papilla, appearing as black dots scattered on the upper surface of leaves. Setae 45–100 × 1.8–3.6 μm (x̅ = 78 × 2.4 μm, n = 10), scattered, dark brown to black at the apex, erect, rounded at the base and wider than the apex. Wall of ascoma 18–32 μm (x̅ = 25 μm, n = 10), thicker at the apex, multi-layered, externally comprising pigmented, dark brown, thick-walled cells of textura angularis, with inner layer thinner, composed of irregularly-shaped, flattened, lightly pigmented to hyaline, thin-walled cells of textura angularis. Hamathecium lacking paraphyses. Asci 48–52 × 13–17 μm (x̅ = 48 × 15.8 μm, n = 10), 8-spored, bitunicate, fissitunicate, clavate to ellipsoid, shortly pedicellate or sessile, with an ocular chamber. Ascospores 18–27 × 3–5 μm (x̅ = 24 × 4.2 μm, n = 10), overlapping uni-seriate or bi-seriate, oblong-ellipsoid, hyaline, 1–3 septate, constricted at the septa, smooth and thick-walled, lacking a gelatinous sheath or appendages. Asexual morph: Undetermined.
Material examined: India, Uttar Pradesh, on leaves of Aegle marmelos (L.) Corrêa (Rutaceae), 16 February 1962, Dwivedi R.S. (IMI 91630).
Figure 2 Chaetothyrium guaraniticum (IMI 91630). a, b Herbarium material. b, c Ascomata on the host surface. e Globose ascoma with black setae. f Mycelial network attaching ascoma to the leaf surface. g, i Vertical sections of ascomata. h Ascomatal setae. i, j Asci with ascospores. Scale bars: c = 500 μm, d = 100 μm, e, g = 50 μm, f = 20 μm, i = 10 μm, j–l = 5 μm.