Hypoxylon xmatkuilense 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

Hypoxylon xmatkuilense P. Reyes, Pinzón, R. Valenz. & Raymundo sp. nov.

Fig. 3

Gen Bank.

ITS ( OR 807999), LSU ( OR 807990), RPB 2 ( OR 825476), TUB 2 ( OR 825467).

Diagnosis.

It characterized by having stromata effused-flattened, surface vinaceous, perithecia obovoid and dark brown KOH-extractable pigments.

Etymology.

from the Mayan Xmatkuil “ place where God is asked ” in reference to the place where it was collected for the first time.

Holotype.

Mexico • Yucatán, east from cemetery, comisaría Xmatkuil ; 14 Oct 2021; P. Reyes leg.; UADY 3 .

Paratypes.

Mexico • ibid.; 11 July 2023; P. Reyes leg.; UADY 118 • ibid; P. Reyes leg.; UADY 119 .

Description.

Stromata effused-flattened, 25–100 mm long × 5–20 mm wide × 1 mm thick, surface pruinose, young stromata have a thin layer Dark Vinaceous (82), when mature this layer is lost, leaving remains that appear Brown Vinaceous (84) (Fig. 3 a ), subsurface blackish, composed of weakly carbonaceous tissue and inconspicuous brownish black granules; perithecia 1.2–1.5 mm diam, obovoid inconspicuous with umbilicate ostioles (Fig. 3 b ); KOH-extractable pigments dark brown (Fig. 3 c ); asci not seen; ascospores 10–12 × 4–5 µm, unicellular, ellipsoid, inequilateral, narrowly rounded ends, with straight 2 / 3 spore-length germ slit on the convex side (Fig. 3 d ), dark brown, perispore dehiscent in 10 % KOH (Fig. 3 e ).

Host.

Growing on dead wood of Gymnopodium floribundum Rolfe ( Polygonaceae ) in deciduous forest

Notes.

It shares the effused-pulvinate to flattened stromata and vinaceous surface with H. lateripigmentum , H. pulicicidum , H. investiens , H. hinnuleum , H. olivaceopigmentum , it differs by having perithecia obovoid, dark brown KOH-extractable pigments and perispore dehiscent ( Ju and Rogers 1996; Bills et al. 2012; Kuhnert et al. 2014 a; Sir et al. 2019); Fournier et al. (2024) described H. aeneipigmentatum as a new taxon from Saül, French Guiana, based on ITS sequences, and noted that it belongs H. investiens complex; moreover reported about a basal perithecial nucleus as a new differential character in this group.

Figures

Figure 3. Hypoxylon xmatkuilense sp. nov a general view of stromata b perithecia obovoid c KOH-extractable pigments d straight germ slit on the convex side e perispore dehiscent 10 % KOH.