Entodesmium Riess, Hedwigia 1(6): 28 (1854)
Saprobic or parasitic? on various dicotyledonous and some monocotyledonous hosts. Sexual state: Ascomata scattered, solitary to gregarious, immersed to erumpent through host tissue with long neck, uniloculate, globose to subglobose, glabrous, dark brown to black, ostiole central, with long neck. Neck with thick walls of textura angularis, dark brown to black, cylindrical to cylindric-clavate, carbonaceous, with periphyses. Peridium thick – walled, composed of brown to dark brown, pseudoparenchymatous cells, arranged in a textura angularis. Hamathecium composed of numerous, filamentous, distinctly septate, broad cellular pseudoparaphyses, not constricted at the septa and anastomosing at the apex. Asci 8 – spored, bitunicate, cylindrical to cylindric – clavate, short pedicellate, apically rounded, with well-developed ocular chamber. Ascospores fasciculate, scolecosporous, filiform or filamentous, initially hyaline to pale brown, becoming brown or reddish-brown at maturity, multi-septate, constricted at the septa, separating into numerous part spores, smooth-walled. Asexual state: Unknown.
Type species: Entodesmium rude
Phylogenetic study: Liew et al. (2000), Schoch et al. (2009), Zhang et al. (2009, 2012)
Notes: Entodesmium was introduced by Riess (1854) and is typified by E. rude. The genus was introduced to accommodate a Dothideomycete species with long beaked ascomata and scolecosporous ascospores, which break into numerous part – spores and occur on legumes. The placement of Entodesmium was previously unclear as Von Arx and Müller (1975) disposed the genus in Pleosporaceae, while Barr (1987b) suggested that Entodesmium should be placed in Phaeosphaeriaceae and this was accepted by Eriksson and Hawksworth (1991). Barr (1992b) assigned Entodesmium to Lophiostomataceae based on its short, blackish beak and periphysate ostiole. Barr (1992b) mentioned that these characters are more typical of Lophiostomataceae. Zhang et al. (2009, 2012) disagreed with Barr (1992b) and mentioned that the morphological characters of Entodesmium best fit in Phaeosphaeriaceae. Entodesmium was thought to be family-specific and associated only with legumes (Barr 1992b; Shoemaker 1984; Zhang et al. 2009, 2012). Holm (1957) and Shoemaker (1984) re-described Entodesmium and reported six species associated with legumes from Europe; although, Wehmeyer (1952) identified some collections from North America (Barr 1992b). Furthermore, there is a report of E. niesslianum from Dieffenbachia (monocotyledon) in West Indies by Minter et al. (2001) in Farr and Rossman (2014). Six species are presently accommodated in Entodesmium; E. eliassonii L. Holm, E. lapponicum (L. Holm) L. Holm, E. mayorii (E. Müll.) L. Holm, E. nevadense Petr., E. niesslianum (Rabenh. ex Niessl) L. Holm and E. rude (Index Fungorum 2014). Entodesmium multiseptatum (G. Winter) L. Holm was assigned to Leptosphaeriaceae and Entodesmium vermisporum (Ellis) M.E. Barr (1992b) was treated in Lophiostomataceae (Winter 1872; Barr 1992b; Zhang et al. 2009, 2012; Index Fungorum 2014). However, Zhang et al. (2009, 2012) mentioned that E. multiseptatum and E. niessleanum are more similar to Phaeosphaeria than Leptosphaeria or Entodesmium. Zhang et al. (2009) accepted the scolecosporous genera Entodesmium and Ophiosphaerella in Phaeosphaeriaceae based on phylogenetic evidence. Multigene phylogenetic analysis based on this sequence data has indicated that Entodesmium belongs to Phaeosphaeriaceae which has been widely accepted (Schoch et al. 2009; Zhang et al. 2009, 2012; Hyde et al. 2013). In this study, the iconotype is re-drawn while the type specimens could not be located. Based on morphology (thinwalled peridium composed of pseudoparenchymatous cells, and scolecosporous, brown, multi septate ascospores breaking into part-spores) and multigene phylogenetic analysis, we retain Entodesmium in Phaeosphaeriaceae. Entodesmium forms a weakly-supported clade with other genera (Chaetosphaeronema, Dematiopleospora, Loratospora, Nodulosphaeria modesta, Ophiobolus cirsii and O. erythrosporus) in Phaeosphaeriaceae. However, the sequence data is from a putative strain of Entodesmium rude from CBS, thus epitypification and molecular work is needed to confirm its natural placement.