Fungalpedia – Note 1592, Neoplaconema
Neoplaconema B. Sutton
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Incertae sedis, Incertae sedis, Incertae sedis, Incertae sedis, Pezizomycotina, Ascomycota, Fungi
Habit on branches of Aconitum napellum, A. toxicum (Ranunculaceae), and on cankered branch of Eucalyptus nitens (Myrtaceae) (Nag Raj 1993, Yuan and Mohammed 1997). Sexual morph: undetermined. Asexual morph: Conidiomata black, pycnidial, solitary to gregarious, epidermal to subepidermal, immersed to erumpent, subglobose, unilocular, sometimes convoluted, glabrous, ostiolate. Ostiole single, circular, centrally located. Conidiomatal wall composed of thick-walled, dark brown to pale brown cells of textura angularis. Conidiophores arising from the inner wall layer of conidiomata, hyaline, cylindrical to dolliform, branched at the base, septate, smooth-walled, invested in mucus. Conidiogenous cells hyaline, enteroblastic, phialidic, lageniform to cylindrical, integrated or discrete, determinate, smooth-walled, with minute, periclinal wall thickened channel and collarette. Conidia hyaline, fusiform to subcylindrical or ellipsoidal, rounded at the apex, slightly truncate at the base, straight or slightly curved, unicellular, smooth-walled, guttulate, bearing a flexuous, curved, unbranched or occasionally forked, cellular appendage separated at the base by a septum (adapted from Nag Raj 1993).
Notes: Neoplaconema was proposed to accommodate a species segregated from Placonema (Sacc. & D. Sacc.) Petr., as N. napelli. This genus has unicellular conidia with an apical appendage similar to Fibulocoela and Rhabdogloeum. However, Rhabdogloeum has acervular conidiomata distinguished from the pycnidial conidiomata in Fibulocoela and Neoplaconema. Fibulocoela has conidiophores with a clamp connection at each septum, a feature not found in Neoplaconema (Nag Raj 1993, this study). Two species are accepted in Neoplaconema, N. cymbiforme Z.Q. Yuan & C and N. napelli, but neither have molecular data. Fresh collections are needed to place Neoplaconema in a natural group.
Type species: Neoplaconema napelli (Maire & Sacc.) B. Sutton, Kew Bull. 31(3): 463 (1977).
Other accepted species: Species Fungorum – search Neoplaconema.
Figure 1 – Neoplaconema napelli (redrawn from Nag Raj 1993) a Vertical section of conidioma. b Conidia. c Conidiogenous cells and developing conidia.
References
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD 2020 – Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.