Carteria canariensis Sastoque, Cano & Stchigel, 2025

Sastoque, A. P., Cano-Lira, J. F. & Stchigel, A. M., 2025, Soil ascomycetes from Spain. XIV. The Chaetomiaceae of La Palma (Canary Islands), Persoonia 54 (1), pp. 93-117 : 99

Carteria canariensis Sastoque, Cano & Stchigel , sp. nov. MycoBank MB 847723. Fig. 4 .

Etymology: The epithet canariensis refers to the Canary Islands, due to the geographic origin of the fungus.

Typus: Spain, Canary Islands, La Palma, Fuencaliente (Los Canarios), from soil of Teneguía volcano, 15 Jul. 2008, coll. M. Calduch & A.M. Stchigel, isol. A.P. Sastoque (holotype CBS H-25242, culture ex-type FMR 18819 = CBS 149955 ) .

On oatmeal agar after 4 wk at 25 °C: Mycelium scarce, mostly aerial, composed of septate, branching, smooth- and thin-walled, subhyaline to reddish brown, 1–2 μm wide hyphae. Ascomata superficial, solitary to aggregated, often covered by aerial mycelium, non-ostiolate, dark brown in reflected light, spherical or subspherical, rarely oblate, 29–65 μm diam. ( Fig. 4E, F ); peridial wall thin, one-layered, brown to reddish-brown, semi-translucent, of textura epidermoidea ( Fig. 4G ). Asci 8-spored, subglobose, ellipsoidal, or obovate, 10–16 × 10–15 μm, without visible stalks, soon evanescent ( Fig. 4H ). Ascospores irregularly-arranged within the asci, 1-celled, dark brown when mature, smooth- and thin-walled, ellipsoidal, (7–)8–9(–10) × (4–)4.5–5(–5.5) μm, attenuated at both ends, occasionally flattened at one side, with a subapical germ pore ( Fig. 4I ). Asexual morph not observed.

Culture characteristics (after 7 d at 25 ° C): Colonies on PCA 8–9 mm diam., circular, flat; margin entire and regular; surface grey (28D1) to greyish green (28F4), with velvety white (5A1) aerial mycelium in the central area, and natural (4B3) colour at the margins; soluble pigment absent; reverse grey (28D1) to greenish grey (28F2), with yellowish white margins (4A2). Colonies on OA 6–7 mm diam., flat, circular; margins entire and regular; surface brownish grey (5C2) and black (6F3) at the centre; soluble pigment absent; reverse uncoloured. Colonies on CMA 6–7 mm diam., flat, circular; margins entire and regular; surface black (6F3) at the centre, surrounded by olive brown (4E4) halo, with yellowish white (3A2) margins; soluble pigment absent; reverse greyish brown (5F3) coloured. Colonies on MEA 11–12 mm diam., flat and circular; margin entire and regular; surface brownish grey (5F2) with scarce dust (5D2) aerial mycelium, surrounded by a grey (5F1) circle and with cream (4A3) margins; soluble pigment present, yellowish; reverse dark grey (1F1) at the centre, surrounded by a sepia (4F4) halo, with yellowish white (4A2) margins. Culture iconography after 4 wk of incubation on PCA, OA, CMA and MEA ( Fig. 4A–D , respectively). Minimum, optimum and maximum temperature of growth on PDA after 7 d: 12 °C, 25 °C and 35 ºC, respectively.

Notes: Carteria canariensis formed a well-supported terminal branch (0.99 PP/82 % BS) as a different species in the monospecific clade of Carteria ( Fig. 1 ), differing from C. arctostaphyli by the production of shorter asci (10–16 × 10–15 μm vs 14–18.5 × 11.5–16 μm in C. arctostaphyli ), ascospores with a typical subapical germ pore (terminal in C. arctostaphyli ), and the production of a yellowish soluble pigment on MEA (not reported for C. arctostaphyli ) ( Wang et al. 2019a).

Figures

Fig. 4.Carteria canariensis CBS 149955. A–D. Colony on PCA, OA, CMA, MEA (4-wk-old; 25 °C; surface, left; reverse, right). E, F. Non-ostiolate ascomata. G. Peridium with textura epidermoidea. H. Asci and ascospores. I. Young and mature ascospores with a subapical germ pore (black arrows). Scale bars: E–G = 25 μm; H, I = 10 μm.

Fig. 1. Maximum likelihood of the tree obtained from the concatenated ITS-LSU-rpb2-tub2 (3215 bp) alignment of the nucleotide sequences from our strains and those retrieved from the GenBank. Bayesian posterior probabilities (PP) ≥ 0.95 and the RAxML bootstrap support values (BS) ≥ 70 % are presented at the nodes (PP/BS). Thickened branches indicate full support (PP = 1 and BS = 100 %). The new species and combinations are indicated in bold. T represents the ex-type strain of the species. NT represents the ex-neotype strain of the species.