Morchella nipponensis Clowez, Izumi, Lamiable, Shibakusa & P. Alvarado

Morchella nipponensis Clowez, Izumi, Lamiable, Shibakusa & P. Alvarado , Mycoscience 63 (6): 282 (2022).

Figs 2 D View Figure 2 , 9 D View Figure 9

Description.

Ascomata lanceolate; attached to the stipe with a small sinus; longitudinally pitted and ridged, with primary vertical ridges and some shorter, secondary vertical ridges, and transecting horizontal ridges. Ridges are slender and finely tomentose; yellow-orange or locally becoming orange brown. Large pits, asymmetrical, deep, flat, and irregular in outline and size; glabrous or finely tomentose; primarily elongated vertically. Stipe cylindrical; slightly swollen in the lower half; glabrous or finely mealy with orange-yellow granules. Context whitish; 1–2 mm thick in the hollow hymenophore; thickened and slightly chambered near the base. Sterile inner surface whitish and pubescent.

Ascospores measuring (15.40 -) 15.53–21.34 (- 21.61) × (9.13 -) 9.56–12.82 (- 12.92) μm (Q = 1.19–2.05, Qm = 1.76 ± 0.21), elliptical to ovoid, with nearly irregular longitudinal and interconnecting transverse ridges; contents homogeneous. Asci cylindrical, eight-spored, frequently (248.50 -) 266.25–340.92 (- 346.30) × (16.98 -) 17.11–24.31 (- 25.21) μm. Paraphyses, cylindrical in shape, apices generally rounded but occasionally subclavate to clavate; septate, (123.28 -) 142.03–365.04 (- 367.07) × (11.04 -) 12.01–20.75 (- 22.92) μm, but difficult to measure their length. Elements on sterile ridges (120.04 -) 121.05–185.19 (- 195.97) × (10.52 -) 11.57–14.9 (- 16.31) μm, difficult to measure their length. The number of ascospores in asci observed to vary from two to eight.

Habitat.

Solitary on the ground around the base of Artemisia sp.

Distribution.

This species is only known from Chongqing, China, and Japan.

Other specimens examined.

China • 1; Chongqing Municipality , Wuxi County, alt. 1697 m, 10 May 2024, Q. Qin ( FCNU 1436 — preserved in the Fungal Herbarium of Chongqing Normal University) . China • 1; Chongqing Municipality , Wuxi County, alt. 1697 m, 10 May 2024, Q. Qin ( FCNU 1437 — preserved in the Fungal Herbarium of Chongqing Normal University) . China • 1; Chongqing Municipality , Wuxi County, alt. 1697 m, 10 May 2024, Q. Qin ( FCNU 1438 — preserved in the Fungal Herbarium of Chongqing Normal University) .

Comments.

Morchella nipponensis is a record new to China. The presence of this species in Chongqing extends its distribution range from Japan to China. That the current disjunct distributions of M. nipponensis in China and Japan are attributed to relatively recent long-distance dispersals or human introductions remains an open question. The macromorphology of the Chinese collection is in accordance with the descriptions of typical M. nipponensis , which was originally described from Japan ( Clowez et al. 2022). Microscopically, the ascospores of Chinese collections are smaller than those reported from Japan, (18 -) 20–23.5 (- 24) × (10.5 -) 11.5–12.5 (- 13) µm, but asci are larger than those from Japan by Clowez et al. (2022). The multi-gene sequences of M. nipponensis generated from the Chinese collections are closely related to that generated from the Japan collection, and the phylogenetic position of this species is well-settled (Fig. 7 View Figure 7 ).