Absidia pyriformis X. Y. Ji, H. Zhao & X. Y. Liu, 2025

Ji, Xin-Yu, Ding, Zi-Ying, Nie, Yong, Zhao, Heng, Wang, Shi, Huang, Bo & Liu, Xiao-Yong, 2025, Unveiling species diversity within early-diverging fungi from China V: Five new species of Absidia (Cunninghamellaceae, Mucoromycota), MycoKeys 117, pp. 267-288 : 267-288

Absidia pyriformis X. Y. Ji, H. Zhao & X. Y. Liu sp. nov.

Fig. 4

Type.

China, Yunnan Province, Pu’er City, Mojiang Hani Autonomous County, Lianzhu Town (23°25'34"N, 101°40'58"E, 1338.32 m), from soil, 4 July 2024, X. Y. Ji and X. Y. Liu, holotype HMAS 353359 , ex-holotype living culture CGMCC 3.28538 (= XG 09540-14-1 ) .

Etymology.

The epithet pyriformis (Lat.) refers to the shape of the sporangia.

Description.

Colonies on PDA at 26 ° C for 5 days, attaining 76 mm in diameter, moderately fast growing with a rate of 15.2 mm / d, white at first, gradually light gray, irregularly at reverse. Hyphae branched, hyaline at first, sometimes brownish when mature, aseptate when juvenile, septate with age, 3.6–15.2 µm (x – = 6.3 µm, n = 20) wide. Stolons branched, hyaline, smooth, septate, 4.5–11.9 µm (x – = 6.9 µm, n = 15) in diameter. Rhizoids well developed, root-like, branched, tapering at the end. Sporangiophores arising from stolons, erect or slightly bent, 2–5 in whorls, monopodial, mostly unbranched or simply branched, smooth, 21.7–279.8 × 1.4–7.4 µm (x – = 97.9 × 4.4 µm, n = 15), with one septum 11.5–26.8 µm (x – = 18.5 µm, n = 15) below apophyses. Sporangia are mostly pyriform, deliquescent-walled, smooth, multi-spored, colorless when young, brownish when old, 11.7–38.8 × 11.0–29.7 µm (x – = 27.9 × 22.1 µm, n = 15). Apophyses distinct, subhyaline, usually brownish when old, 5.0–8.4 µm (x – = 7.0 µm, n = 15) high, 2.4–6.1 µm (x – = 4.4 µm, n = 15) wide at the base, and 8.9–19.2 µm (x – = 12.5 µm, n = 15) wide at the top. Collars distinct. Columellae hemispherical, subglobose to globose, smooth, subhyaline or brownish, 8.8–21.4 × 16.7–20.7 µm (x – = 10.9 × 16.7 µm, n = 15). Projections at the apex, when smaller, with an oval projection. Sporangiospores hyaline, smooth, almost cylindrical, 3.2–4.5 × 1.7–2.8 µm (x – = 3.9 × 2.2 µm, n = 20). Chlamydospores absent. Zygospores absent.

Maximum growth temperature.

33 ° C.

Additional specimen examined.

China • Yunnan Province, Pu’er City , from soil (23°25'34"N, 101°40'58"E, 1338.32 m), 4 July 2024, X. Y. Ji and X. Y. Liu, living culture XG 09540-14-5 .

Notes.

Phylogenetically, A. pyriformis was closely related to A. soli ( Hurdeal et al. 2021) . Compared with A. soli , the A. pyriformis presented a smaller sporangia size (11.7–38.8 × 11.0–29.7 µm vs. 16–51 × 15–45.5 µm), and the septum showed at a shorter distance from apophyses (11.5–26.8 µm vs. 21.5–37.5 µm); conversely, sporangiophores exhibited a larger size (3.2–4.5 µm vs. 1.7–2.8 µm), and columellae had a longer length (8.8–21.4 µm vs. 7.5–12.5 µm).

Figures

Figure 4. Absidia pyriformis ex-holotype CGMCC 3.28538 a, b colonies on PDA (a obverse b reverse) c, d sporangia e – g columellae h rhizoids i sporangiospores; Scale bars: 10 µm (c – i).