Published April 28, 2023 | Version v1
Taxonomic treatment Open

Rhexoacrodictys melanospora S. X. Bao, R. J. Xu & Q. Zhao 2023, sp. nov.

  • 1. Yunnan Key Laboratory of Fungal Diversity and Green Development, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand & baosx 016 @ gmail. com; https: // orcid. org / 0000 - 0002 - 8223 - 6556
  • 2. Yunnan Key Laboratory of Fungal Diversity and Green Development, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand & xurongju 1005 @ outlook. com; https: // orcid. org / 0000 - 0002 - 3968 - 8442
  • 3. College of Landscape and Horticulture, Yunnan Agricultural University, Kunming, Yunnan 650201, China & zhuyingan 2013 @ 163. com; https: // orcid. org / 0000 - 0001 - 6325 - 8605
  • 4. Yunnan Key Laboratory of Fungal Diversity and Green Development, Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China & zhaoqi @ mail. kib. ac. cn; https: // orcid. org / 0000 - 0001 - 8169 - 0573

Description

Rhexoacrodictys melanospora S.X. Bao, R.J. Xu & Q. Zhao, sp. nov.

Index Fungorum Number: IF559983.

Facesoffungi Number: FoF 12898; Fig. 2.

Etymology: The specific epithet ‘ melanospora ’ refers to the dark conidia of the fungus

Saprobic on decaying woods in terrestrial habitat. Sexual morph: Undetermined. Asexual morph: Conidiophores 19–60 × 3–5 μm (Q = 40 × 4 μm, n = 20), macronematous, mononematous, erect, straight or somewhat fexuous, pale brown to brown, cylindrical, thick-walled, smooth, 2–4 septate. Conidiogenous cells 2–6 × 3–4 μm (Q = 4 × 3.5 μm, n = 10), monoblastic, integrated, terminal, pale brown, cylindrical, with 1–3 pale brown percurrent extensions. Conidia 16–32 × 12–21 μm (Q = 23 × 16 μm, n = 40), solitary, acrogenous, ellipsoidal to obovoid or somewhat subglobose, muriform, with 2–5 transverse and several oblique septa, pale brown when immature, becoming dark brown at maturity, thick and smooth-walled.

Culture characteristics: Colonies on PDA, reaching 4 cm diam. after 15 days at room temperature (25 ˚C), colonies irregular, surface taupe, mycelium dense, and reverse blackish.

Material examined:— CHINA. Yunnan Province, Fugong County, decayed wood in terrestrial habitats, 13 May 2021, Song Wang, GLG41-1 (HKAS 124580, holotype), ex-type KUNCC 22-12406; China, Derung-Nu Autonomous County of Gongshan, 15 May 2021, Song Wang, GLG41-2 (HKAS 124581, paratype), ex-paratype KUNCC 22- 12411.

Notes: Rhexoacrodictys melanospora is easily distinguished by its macronematous, conidiophores, and conidia ellipsoidal, 2–5 transverse, and several oblique septate. R. melanospora clustered with R. erect and R. fimicola with strong bootstrap support (100% ML/1.00 BI). However, R. melanospora has shorter conidiophores than R. fimicola (19–60 μm vs. up to 75 μm) (Baker et al. 2002), R. erect has numerous irregular septa, and R. melanospora just has 2–5 transverse and several oblique septa (Baker et al. 2002, Zhao et al. 2011).

Among the four species of Rhexoacrodictys (Index Fungorum 2023), R. broussonetiae and R. fuliginosa lack DNA sequences. Although their molecular data deficiency, R. melanospora clearly differs from R. broussonetiae and R. fuliginosa by its shorter conidiophores, 19–60 μm (vs. 70–90 μm in R. broussonetiae, and vs. up to 85 μm in R. fuliginosa) and longer conidia, 16–32 μm (vs. 17–28μm in R. broussonetiae, and vs. 17–27 μm in R. fuliginosa) (Baker et al. 2002, Zhao et al. 2011, Xiao et al. 2018).

A morphological comparison of Rhexoacrodictys species is summarized in Table 2 and a photo plate of R. melanospora is in Fig. 2.

Notes

Published as part of Bao, Shu-Xin, Xu, Rong-Ju, Zhu, Ying-An & Zhao, Qi, 2023, Rhexoacrodictys melanospora sp. nov. (Rhexoacrodictys, Pleurotheciales) from Yunnan, China, pp. 213-222 in Phytotaxa 594 (3) on pages 217-219, DOI: 10.11646/phytotaxa.594.3.5, http://zenodo.org/record/7901294

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Linked records

Additional details

Biodiversity

Event date
2021-05-13
Verbatim event date
2021-05-13/15
Scientific name authorship
S. X. Bao, R. J. Xu & Q. Zhao
Kingdom
Fungi
Phylum
Ascomycota
Order
Distoseptisporales
Family
Distoseptisporaceae
Genus
Rhexoacrodictys
Species
melanospora
Taxon rank
species
Taxonomic status
sp. nov.
Type status
holotype
Taxonomic concept label
Rhexoacrodictys melanospora Bao, Xu & Zhao, 2023

References

  • Baker, W. A., Partridge, E. C. & Morgan-Jones, G. (2002) Notes on Hyphomycetes. LXXXVII. Rhexoacrodictys, a new segregate genus to accommodate four species previously classified in Acrodictys. Mycotaxon 82: 95 - 113.
  • Zhao, G. Z., Cao, A. X., Zhang, T. Y. & Liu, X. Z. (2011) Acrodictys (Hyphomycetes) and related genera from China. Mycological Progress 10: 67 - 83. https: // doi. org / 10.1007 / s 11557 - 010 - 0677 - 2
  • Index Fungorum (2023) Available at: http: // www. indexfungorum. org / (Accessed 18 April 2023)
  • Xiao, Z. J., Li, X. X., Wang, H. D., Song, P. Y. & Tang, L. (2018) Rhexoacrodictys broussonetiae sp. nov. from Guizhou, China. Mycotaxon 133 (1): 149 - 152. https: // doi. org / 10.5248 / 133.149