Fungalpedia – Note 3222, Atractium
Atractium. Link.
Citation when using this data: Bao DF et al. 2023– Fungalpedia.
Index Fungorum, Facesoffungi, MycoBank, GenBank
Classification: Nectriaceae, Hypocreales, Hypocreomycetidae, Sordariomycetes, Pezizomycotina, Ascomycota, Fungi
≡ Varicosporella Lechat & J. Fourn
Sexual morphs: Ascomata on submerged wood, superficial, nonstromatic, obpyriform, pale orange, turing or not turning red or purple in 3% KOH, turning pale yellow in lactic acid. Predium composed of angular to flattened cells. Hamathecium composed of fugacious moniliform paraphyses. Asci 8-spored, cylindric-clavate with a J- flat- tened apical apparatus. Ascospores uniseriate, ellipsoid to fusiform, 1-septate, slightly constricted at septum, hyaline to pale-yellow brown, ornamented with short sinuous ribs (Lechat and Fournier 2015). Asexual morphs: See Gräfenhan et al. (2011).
Notes: Atractium was established with A. stilbaster as the type species by Link (1809). Link (1825) reinterpreted the generic concept of Atractium to include the pale or colourful synnematous taxa with slimy conidial masses, usually with falcate, septate conidia. The genus was previously listed as a synonym of Fusarium (Wollenweber and Reinking 1935). However, Atractium has synnematous conidiophores which is different from Fusarium. Hence, Gräfenhan et al. (2011) proposed them as two distinct genera. In addition, the epitype of A. stilbaste (the type of Atractium) was designated by Gräfenhan et al. (2011), and they accepted three species (A. crissum, A. holubovae and A. stilbaster) in Atractium. Currently, 26 names of Atractium are listed in the Index Fungorum (2023), of which only three species are accepted in the genus while the placement of the other 23 species remains uncertain (Gräfenhan et al. 2011). Atractium species are commonly associated with water (Gräfenhan et al. 2011) and species in the genus have been found from Canada, Germany, and the Philippines (Seifert 1985; Seifert et al. 1995; Sivichai et al. 2002; Fryar et al. 2004).
Atractium is only known by its asexual morphs and is characterized by synnematous conidiophores branching once or twice monochasial, 2-level verticillate, monoverticillate or irregularly biverticillate; monophialidic, hyaline, subulate conidiogenous cells and septate, clavate, obovoid or gently curved, rarely ellipsoidal, conidia with a rounded apical cell, and somewhat conical basal cell, lacking a differentiated foot, some species produce chlamydospores (Gräfenhan et al. 2011). In this study, a sexual species Varicosporella aquatica is transferred to Atractium and a new species Atractium fusiformis is introduced based on morphological and phylogenetic analyses. The morphological description of sexual morph of this genus is also provided.
Type species: Atractium stilbaster Link, Mag. Gesell. naturf. Freunde, Berlin 3(1-2): 10 (1809)
Other accepted species: Species Fungorum – search Atractium.
References
Link JHF 1825 – Caroli a Linne Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas. Impensis G. C. Nauk, Berolini 6(2):106.
Seifert KA, Stanley SJ, Hyde KD. 1995 – Stilbella holubovae, a new synnematous hyphomycete species on driftwood from the Philippines and South Africa. Sydowia 47:258–262.
Wollenweber HW, Reinking OA. 1935 – Die Fusarien: ihre Beschreibung. Schadwirkung und Bekampfung, Berlin, pp 1–355.
Entry by
Bao Dan‑Feng, College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, P.R. China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand, Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand.
Published online 28 September 2026