Hypocreopsis rhododendri Thaxt., Proc. Amer. Acad. Arts & Sci.

Zeng, Zhao-Qing, Wang, Xiang-Hua & Zhuang, Wen-Ying, 2024, New species and new Chinese record of Hypocreaceae from China, Phytotaxa 650 (1), pp. 93-102 : 98

Hypocreopsis rhododendri Thaxt., Proc. Amer. Acad. Arts & Sci. 57(17): 429, 1922.

Fig. 4

Specimen examined:— CHINA. Yunnan Province:Yulong County, Jiuhe Town, Laojunshan, E99.812461 N26.655211, alt. 2912 m, on rotten branch of Tsuga dumosa , 25 July 2019, X.H. Wang et al. 6039 (HKAS 131916).

Description:— Stromata developing as radiating ridge, up to 28 mm diam., 2.5–4.8 mm wide, 1–5 mm thick, divided in marginal areas into separate lobes. Stromata yellowish brown when fresh and brown when dry, KOH–. Surface smooth on young lobes, becoming rugose in central areas. Perithecia flask-shaped to subglobose, 195–462 μm high, 160–280 μm diam. Papilla prominent, blunt or truncate, brown, 20–40 μm high, 45–80 μm wide. Asci cylindrical, containing 8 ascospores, 65–74 × 6–9.6 μm. Ascospores globose to subglobose, ellipsoidal, verrucose, 4.5–9.5 × 4.5–9.3 μm. Asexual state unknown.

Distribution:— China, Eire, France, UK, USA ( Thaxter 1922, Dennis 1975, Candoussau 1990, Rossman et al. 1999, Hansen & Knudsen 2000, Ainsworth 2003).

Notes:— Hypocreopsis rhododendri was introduced by Thaxter (1922) based on specimens collected on stems and branches of Rhododendron maximum from North Carolina and Tennessee, USA early in 1888. Later it was discovered from UK, Eire and France ( Ainsworth 2003). The morphology of the Yunnan collection fits well the original description of the species. In GenBank there is no available data from North American samples. The ITS sequence of the Chinese specimen is identical with those from UK provided by Grundy et al. (2012). Another species H. lichenoides is very similar in gross morphology, but has elongate ascospores with tapering ends ( Thaxter 1922, Ainsworth 2003). The Oceanic H. amplectens is related in the ITS phylogeny ( Fig. 2 ). The (2–)3–4-spored asci and much longer multiseptate ascospores of H. amplectans makes it clearly distinguishable from H. rhododendri ( Johnston et al. 2007) .

Figures

FIGURE 2. The ML tree inferred from ITS sequences of representative species of Hypocreopsis and Hypomyces. MLBP (≥70%) and BIPP (≥0.9) are shown at the nodes.

FIGURE 4. Hypocreopsis rhododendri. a Fresh stromata on natural substrate. b. Dry stromata on rotten trunk. c. Close-up view of perithecia. d. Perithecia after rehydration. e. Median section through stroma. f. Section of cortical tissue and perithecial ostiole. g. Subperithecial tissues in section. h. Perithecium in section. i–n. Asci with ascospores. Scale bars: a, b = 1 cm, c, d = 1 mm, e–h = 50 μm, i–n =10 μm.