Two new species and a new record of Hypoxylaceae (Xylariales, Ascomycota) from Mexico Author Reyes, Pamela E. 0000-0003-0882-5245 Campus de Ciencias Biológicas y Agropecuarias, Laboratorio de Recursos Florísticos de Mesoamérica, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, Plan de Ayala ÌII, Mérida 97100, Yucatán, Mexico Author Pinzón, Juan Pablo 0000-0002-0964-2996 Campus de Ciencias Biológicas y Agropecuarias, Laboratorio de Recursos Florísticos de Mesoamérica, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, Plan de Ayala ÌII, Mérida 97100, Yucatán, Mexico Author Valenzuela, Ricardo Laboratorio de Micología, Departamento de Botánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s / n, Col. Santo Tomás, Miguel Hidalgo, Ciudad de México 11350, Mexico Author Raymundo, Tania 0000-0002-7525-0034 Laboratorio de Micología, Departamento de Botánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s / n, Col. Santo Tomás, Miguel Hidalgo, Ciudad de México 11350, Mexico Author Tun-Garrido, Juan 0000-0001-8796-3405 Campus de Ciencias Biológicas y Agropecuarias, Laboratorio de Recursos Florísticos de Mesoamérica, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, Plan de Ayala ÌII, Mérida 97100, Yucatán, Mexico Author García-Sandoval, Ricardo 0000-0001-8641-3305 Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior s / n, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico text MycoKeys 2024 2024-12-17 111 111 127 journal article 306593 10.3897/mycokeys.111.133046 524e4c09-fbe7-4540-9a7e-c14d9a6894cd 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 ). 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. 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.