Hypohelion shennongjianum Lan Zhuo & C. L. Hou, 2025

Hypohelion shennongjianum Lan Zhuo & C. L. Hou sp. nov.

Figs 15 View Figure 15 , 16 View Figure 16

Etymology.

Referring to the name of the location in the Shennongjia forestry region where the type specimen was collected.

Diagnosis.

This new species is similar to Coccomyces anhuiensis T. Lv & C. L. Hou , but differs by intraepidermal ascomata and ascospores with an apical gelatinous cap, having 4–6 short filament-like appendage on the gelatinous cap.

Type.

CHINA, Hubei Province, Shennongjia forestry region, Muyuzhen , 31.4200°N, 110.4030°E, alt. ca. 1560 m, on twigs of Cunninghamia lanceolata (Lamb.) Hook. ( Cupressaceae ), 20 Jul. 2018, C. L. Hou & T. Lv. HOU 1342 A ( BJTC 2018037 , holotype) GoogleMaps .

Sexual morph.

Ascomata on young and dead twigs, scattered, not associated with pale areas. In surface view, ascomata wide elliptical to irregular elliptical, 650–950 × 350–500 µm, black (# 000000), or black in the center and gray (# 787870) towards the margin, shiny, with black perimeter line, opening by an irregular, longitudinal, 3 - teethed split. Lips absent. In median vertical section, ascomata intraepidermal. Covering stroma 30–35 μm thick near the center of ascomata, extending to the basal Covering stroma, consisting of an outer layer of host cuticle and an inner layer of carbonized, thick-walled angular cells. Basal Covering stroma 15–20 µm thick, consisting of carbonized, thick-walled, angular cells. Triangular space visible in vertical section between the covering stroma and the basal Covering stroma at margin of ascoma filled with thin-walled angular, globose cells. Subhymenium 10–15 µm thick, consisting of hyaline textura intricata. Excipulum well-developed, formed by marginal paraphyses. Paraphyses aseptate, filiform, not branched, not swollen at tips, 120–140 × 1–2 µm. Asci ripening sequentially, clavate, apex bluntly pointed, 70–90 × 6–10 µm, thin-walled, J –, 8 - spored. Ascospores aseptate, clavate, 35–45 × 2–3 μm, hyaline, multi-guttulate when immature, covered by thin gelatinous sheaths, with a gelatinous cap at the tip of mature ascospores, with 4–6 short filament-like appendages on each gelatinous cap.

Asexual morph.

see Notes. Zone lines infrequent, diffuse, black.

Distribution.

Known only from Hubei Province, China.

Notes.

Based on the phylogenetic analysis, Hy. shennongjianum clusters with the type of the genus Hypohelion , Hy. scirpinum , as well as Hy. anhuiense , with weak support (Clade 5, Fig. 1 View Figure 1 ). Morphologically, Hy. shennongjianum shares clavate ascospores with other species of Hypohelion , but the shape of its ascomata is distinct from other Hypohelion species and resembles that of Coccomyces anhuiensis . However, unlike Co. anhuiensis , Hy. shennongjianum has intraepidermal ascomata and ascospores carry a gelatinous cap at the tops, bearing 4–6 short filament-like appendages on the gelatinous cap. Considering both its phylogenetic position and morphological characteristics, this new species should be placed in the genus Hypohelion .

A probable asexual morph was observed in association with Hy. shennongjianum . The conidiomata are scattered, occasionally confluent, elliptical, reddish brown (# 68271 a), and 100–200 × 200–350 µm in size. In vertical section, the conidiomata are intraepidermal, 80–100 µm deep, with an upper layer 25–30 µm thick, composed of host cuticle and carbonized angular to globose cells, and a basal layer 15–18 µm thick, consisting of similar carbonized cells. Conidiogenous cells and conidia were not observed. Sequencing of the conidiomata was attempted but unsuccessful, so molecular data does not currently support the connection.