Annulohypoxylon fusisporum P. Reyes, Pinzón, R. Valenz. & Raymundo, 2024

Reyes, Pamela E., Pinzón, Juan Pablo, Valenzuela, Ricardo, Raymundo, Tania, Tun-Garrido, Juan & García-Sandoval, Ricardo, 2024, Two new species and a new record of Hypoxylaceae (Xylariales, Ascomycota) from Mexico, MycoKeys 111, pp. 111-127 : 111-127

Annulohypoxylon fusisporum P. Reyes, Pinzón, R. Valenz. & Raymundo sp. nov.

Fig. 2

Gen Bank.

ITS ( OR 807998), LSU ( OR 807987), RPB 2 ( OR 825472), TUB 2 ( OR 825468).

Diagnosis.

It is characterized by having fusiform spores 10–12 × 4–5 µm, grayish green to dull green KOH-extractable pigments, ¼ perithecial mounds exposed, with straight germ slit in spore-length on the convex side.

Etymology.

in reference to the fusiform spores.

Holotype.

Mexico • Quintana Roo, Bacalar Experimental Station , Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias; 10 March 2023; P. Reyes leg.; UADY 83 .

Description.

Stromata effused-pulvinate 20–70 mm long × 20–30 mm wide × 1 mm thick, surface dark brown to black (Fig. 2 a ) inconspicuous perithecial mounds up to 1 / 4 exposed (Fig. 2 b ) dark brown to black granules beneath surface, KOH-extractable pigments Grayish Green (50) changing to Dull Green (70) after 1 minute (Fig. 2 c ) perithecia 0.7–0.8 mm diam, spherical, conical- papillate ostioles surrounded with a truncatum type disc 0.2–0.25 mm diam; asci 8 - spored cylindrical, the spore bearing parts 60–75 µm long × 5–7 µm wide, stipes 20–45 µm long, with amyloid, discoid apical apparatus, 1–2 µm high × 2 µm wide (Fig. 2 d ); ascospores 10–12 × 4–5 µm, unicellular, fusiform with narrowly rounded ends, with faint, straight germ slit along the spore on the convex side (Fig. 2 e ), light brown, perispore dehiscent 10 % KOH (Fig. 2 f ).

Host.

Growing on dead wood of Brosimum alicastrum ( Moraceae ) in subevergreen forest.

Notes.

It is similar to A. subeffusum ( Hladki and Romero 2009) due to the color, shape of the stromata and the grayish green pigments, however the ascospores of this one are smaller 7–10 × 3–3.8 µm and have inconspicuous perithecial mounds. With A. leptascum it shares fusiform shape spores, unlike the length of the germ slit which is short, and the pigments are olive-colored, not changing after 1 minute in 10 % KOH; Kuhnert et al. (2016) found BNT, truncatone A and truncatone C in aforementioned taxa.

Figures

Figure 2. Annulohypoxylon fusisporum sp. nov. a general view of stromata b perithecia spherical with truncatum type ostiolar disc c KOH-extractable pigments d asci e straight germ slit f perispore dehiscent 10 % KOH.