Fungalpedia – Note 591, Lachnum
Lachnum Retz.
Citation when using this data: Zhang et al. 2025 – Fungalpedia. Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification:Lachnaceae, Helotiales, Leotiomycetidae, Leotiomycetes, Pezizomycotina, Ascomycota, Fungi
Lachnum has traditionally been assigned to Hyaloscyphaceae (Cantrell and Hanlin 1997; Hosoya et al. 2010), until the tribe Lachneae was raised to the familial rank of Lachnaceae based on their morphological distinctions (Raitviir 2004). This treatment was supported by subsequent studies (Ekanayaka et al. 2019; Wijayawardene et al. 2022). Moreover, ITS and rpb2 was proposed as significant DNA barcodes for delimitation of Lachnum species phylogenetically (Hosoya et al. 2010; Zhao and Zhuang 2011). Morphologically, Lachnum is characterized by small, discoid, stipitate or casually sessile apothecia covered by totally granulate, hyaline or brown hairs equipped with crystals or resinous matters at their apices; ectal excipulum composed of hyaline or brownish cells textura prismatica usually or sometime textura angularis; pure white to yellow or reddish hymenium; lanceolate to subcylindrical paraphyses which extending over the asci at various degrees usually; subcylindrical to clavate asci with an amyloid apical ring; and ascospores with diverse shapes (Nannfeldt 1932; Spooner 1987; Ye et al. 2006; Hosoya et al. 2010; Hongsanan et al. 2015). As several genera within Lachneae, such as Albotricha, Lachnum, Trichopeziza and Trichopezizella, share similar morphology in hairs, asci, paraphyses, and ectal structures, molecular data is significant for species taxonomy (Nannfeldt 1932; Spooner 1987; Raitviir 2004; Hosoya et al. 2010). Hosoya et al. (2010) provided a key to the lachnoid genera based on phylogeny using diagnostic characters.
The genus Lachnum has a worldwide distribution, occurring on various plant substrates including ferns, herbs, and coniferous or broadleaved trees from temperate and tropical regions (Dennis 1961; Haines 1980; Haines 1984; Wu 1998; Zhuang and Hyde 2001; Ye et al. 2006; Wu and Su 2007; Hosoya et al. 2010). Index Fungorum (2024) has listed 532 epithets under Lachnum, and 50 species were accepted in this genus (Wijayawardene et al. 2022). Among these, 19 species of Lachnum and four unidentified Lachnum species are associated with pteridophytes worldwide.
Type species: Lachnum virgineum (Batsch) P. Karst.
Other accepted species: Species Fungorum – search Lachnum.
Figure 1 – Lachnum virgineum. a Apothecia. b Asci. c Lanceolate paraphyses with subacute tips. d Cylindrical hairs with enlarged apices. e Ascospores. Scale bars: b–e = 10 µm. Redrawn from Sukova (2005).
References
Dennis R 1961 – Some inoperculate discomycetes from New Zealand. Kew Bulletin 15 (2):293–320.
Haines J 1980 – Studies in the Hyaloscyphaceae I. Some species of Dasyscyphus on tropical ferns. Mycotaxon 11:189–216.
Raitviir A 2004 – Revised synopsis of the Hyaloscyphaceae. Scripta Mycologica 20:1–133.
Wu ML 1998 – New species and records of Lachnum from Taiwan. Mycotaxon 67:341–353.
Zhuang W 2001 – Higher fungi of tropical China. Mycotaxon Ltd Ithaca, New York.
Entry by
Jing-Yi Zhang, School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, 550025, People’s Republic of 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, Guizhou Key Laboratory of Agricultural Microbiology, Guizhou Academy of Agricultural Sciences, Guiyang, 550009, People’s Republic of China.
Published online 23 July 2025