Karstenula lancangensis

Karstenula lancangensis G.C. Ren and K.D. Hyde, Biology 11(no. 1660): 15 (2022)

Index Fungorum number: IF 559808; Facesoffungi number: FoF 10706.

Saprobic on dead woody twigs of Cinnamomum glanduliferum. Sexual morph: undetermined. Asexualmorph: Conidiomata 270–480 µm high × 240–430 µm diam. (= 410 × 350 µm, n = 5), pycnidial, solitary, immersed, unilocular or bilocular, obpyriform, black conidiomata formed under the bark, with broadly rounded apex, and a broad pore opening. Conidioma wall 30–40 µm wide, 4–6-layered, composed of an outer layer of brown cells and an inner layer of hyaline cells of textura angularis. Conidiophores reduced into conidiogenous cells. Conidiogenous cells 4–6.5 × 4.4–6.4 µm ( = 5.3 × 5.4 µm, n = 15), holoblastic, ampulliform-to-doliiform, determinate, hyaline with conspicuous periclinal thickening. Conidia 8–10 × 3–4 µm ( = 8.8 × 3.6 µm, n = 30), oval-to-ellipsoid, straight, aseptate or 1-septate, initially hyaline, becoming brown, cylindrical at maturity, 1-septate (median), partly dark brown septum at median, not constricted at the septum, apex and base rounded, thick-, and smooth-walled.

Culture characteristics: The colonies on PDA reached 45–50 mm diam. after 14 days at room temperature (25–30 ºC), superficial, with sparse mycelia, circular, rough, granular, gray-white; reverse dark brown.

Material examined: China, Yunnan Province, Lancang, Lahu Autonomous Prefecture, Hani (22º24.381´ N, 100º06.647´ E, elevation 900 m), on dead woody twigs of Cinnamomum glanduliferum, 23 March 2020, G.C. Ren, W07 (HKAS 122790, holotype), ex-type culture KUMCC 21-0670; ibid., W08 (HKAS 122888, isotype), living culture KUMCC 21-0677.

Notes: Karstenula lancangensis is introduced as a new species based on its distinct morphology and its phylogenetic position. In the phylogenetic analyses, K. lancangensis formed a sister clade to K. rhodostoma with 100% ML bootstrap and 1.00 BYPP support. Karstenula lancangensis shows similar morphological features to K. rhodostoma in having cylindric, 1-septate, brown conidia. However, the size of the conidia of K. lancangensis (8–10 _ 3–4 _m) is comparatively smaller than those of K. rhodostoma (10–)11–13 (–14) _ (4–) 4.5–5 (5.5) _m). In addition, the conidiomata of K. lancangensis are unilocular or bilocular, obpyriform with a broadly rounded apex and broad pore, while they are unilocular, globose with a 100 × 80 µm ostiolate in K. rhodostoma.

Figure 1. Phylogram generated from ML analysis based on the combined SSU, LSU, ITS, and tef 1- dataset. Bootstrap support values for ML equal to or higher than 75%, and BYPP equal to or greater than 0.90 are shown above the nodes.