Melanconis groenlandica (M. Bohn) L. Lombard & Crous

Wang, Caixia, Jiang, Ning, Liu, Chuli, Xu, ZiYan, Lu, Hailong & Ma, Rong, 2025, Morphology and molecular phylogeny reveal new species and records of Diaporthales from Betula in Xinjiang, China, MycoKeys 125, pp. 167-204 : 167-204

Melanconis groenlandica (M. Bohn) L. Lombard & Crous , Persoonia 36: 234 (2016)

Fig. 12

Description.

Conidiomata acervular, semi-immersed in the bark, scattered, conical, 1050–1400 μm diam., 450–700 μm high. Central column beneath the disc conical, pale yellow. Ectostromatic disc dark brown to black, circular to ovoid, 400–450 μm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells cylindrical, smooth, hyaline, producing a conidium at apex, (25 –) 32–38.5 (– 40) × 2.5–3.5 (– 4) μm. Alpha conidia brown, aseptate, ovoid, (8.5 –) 9.5–11 (– 11.5) × (6 –) 6.5–7.5 (– 8) (av. = 10.2 ± 0.7 × 7.1 ± 0.4, n = 50) μm, L / W ratio = 1.3–1.6.

Culture characteristics.

Colonies on PDA flat, spreading, with sparse to moderate aerial mycelium and undulate margin, rosy to fawn, reaching 80 mm diam. after 2 weeks at 25 ° C.

Materials examined.

China • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Zhaosu County, Xiata Ancient Trail National Forest Park , from branches of Betula tianschanica , 6 September 2023, Rong Ma, Chuli Liu, Caixia Wang & Wanbin Shi ( XJAU 3812 , cultures CFCC 71566 , CFCC 71567 , CFCC 71568 , CFCC 71569 ) .

Notes.

Melanconis groenlandica has been reported from the USA and Japan, where it occurs on Betula maximowicziana , B. nana and B. papyrifera ( Bohn 1993; Jaklitsch and Voglmayr 2020). This fungus is known to exhibit an endophytic lifestyle in Betula hosts and its morphological characteristics were originally described in Bohn (1993) with illustrations (conidial size 9–15 × 5–7 μm). In the present study, we provide the first description of this species on its natural host, based on newly-collected specimens showing similar conidial characteristics to the holotype ( Bohn 1993). Furthermore, this represents the first record of M. groenlandica on Betula tianschanica and its occurrence in China.

Figures

Figure 12. Morphology of Melanconis groenlandica from Betula tianchanica. A – C. Habit of conidiomata on branch; D. Transverse section through conidiomata; E. Longitudinal section through conidiomata; F. Conidiophores and conidiogenous cells; G. Alpha conidia. Scale bars: 500 μm (B – E); 10 μm (F, G).