Tengochaeta bulbillosa Y. Marin & D. Barrera-Adame 2025, sp. nov.

Tengochaeta bulbillosa Y. Marin & D. Barrera-Adame sp. nov. Fig. 2 Etymology. Named after the formation of bulbils. Type material. AUSTRIA: Kammer, Sarastro Stauden, roots of Aster tataricus, Oct. 2019, isol. D. A. Barrera-Adame, ident. Y. Marin-Felix (holotype CBS H-25355; ex-type cultures CBS 151409). Description. Mycelium composed of hyaline to subhyaline or pale brown, septate, smooth-walled to verrucose, branched hyphae, 1–5 µm diam. Bulbils spherical to irregular, pale brown to dark brown, up to 9.5–70 µm diam, composed of globose to ellipsoidal or irregularly globose, pale brown to brown, smooth and thick-walled cells, 4.5–11 µm diam. Culture characters. Colonies on MEA attaining a diam. of 35–45 mm in 7 d at 25 ° C, cottony, umbonate, circular to slightly lobate, margins fringed, grayed yellow (162 A – D); reverse yellow orange (17 A – D) and center grayed orange (166 B). Colonies on OA attaining a diam. of 52–55 mm in 7 d at 25 ° C, velvety to cottony, umbonate, circular, margins regular, grayed orange (167 A – B), margins transparent to white, mycelia and center orange white (159 B – C); reverse grayed orange (177 B – C). Colonies on PCA attaining a diam. of 48–52 mm in 7 d at 25 ° C, cottony, hemispherical, circular to slightly lobate, margins fringed, yellow orange (16 B – D) and white mycelia; reverse orange (26 A – B), margins yellow (13 B – C), and center grayed orange (177 A). Colonies on PDA attaining a diam. of 30–32 mm in 7 d at 25 ° C, velvety to cottony, center folded, circular to slightly lobate, margins fringed, yellow (12 C – D), ring yellow orange (20 C), margins white; reverse yellow orange (20 A – C) with center grayed orange (174 B). Notes. Tengochaeta bulbillosa, which produces bulbils, is only the second species reported in the genus. Tengochaeta nigropilosa, which was isolated from soil in a Pinus forest in Spain, produces sexual morph characterized by ascomata with flexuous to undulate hairs, pyriform or broadly clavate asci and ellipsoidal to fusiform ascospores. No asexual morph has been observed in the latter species. Bulbils have only been reported in two other genera of the family Chaetomiaceae, i. e. Subramaniula and Trichocladium (Wang et al. 2022). However, in the latter genus, the propagules are hyaline, while in our new species of Tengochaeta, they are pale brown to dark brown. The bulbils reported in different species of Subramaniula, i. e. S. anamorphosa, S. asteroides and S. obscura, are also pigmented (Ahmed et al. 2016). Bulbils in T. bulbillosa are smaller (9.5–70 µm diam) than in S. asteroides (58–100 × 44–71 µm) and S. obscura (27–73 × 20–36 µm). Comparison of the size of bulbils with S. anamorphosa is not possible due to the lack of this information in the original description. Moreover, cells composing the bulbils are larger in S. asteroides (7–12 × 7–9 µm) than in T. bulbillosa (4.5–11 µm diam) (Ahmed et al. 2016).