Mytilinidiales » Mytilinidiaceae » Septonema

Septonema secedens

Septonema secedens Corda, Icon. fung. (Prague) 1: 9 (1837).

            Index Fungorum number: IF 153626; Facesoffungi number: FoFxxx, Fig. 1


The morphology is as follows: Saprobic on host. Asexual morph: Colonies on natural substrate orbicular, densely floccose, dark brown or dark reddish brown, typically confluent and forming irregular patches, occasionally effuse and hairy. Mycelium superficial comprising branched, septate, strongly verruculose, echinulate, verrucose or strongly verrucose, pale brown to dark brown ascending hyphae, often anastomosing, interwoven creeping hyphae, often constricted at the septa and forming angular or irregularly swollen cells, 3.1−4.2 μm wide. Conidiophores variable in size, macronematous or semi-macronematous, mononematous, arising terminally or laterally from the hyphae, solitary, erect or somewhat repent, flexuous or sinuous, rarely straight, cylindrical or sub cylindrical, mostly branched, septate, occasionally constricted at some septa and breaking along the constrictions, verruculose, smooth, thick-walled, brown to reddish brown, ornamentation vary along the length of the conidiophore. Conidiogenous cells 6.0−6.9 × 2.3−3.5 µm (x̄ = 6.5 × 3.0 µm, n = 10), monoblastic or polyblastic, integrated, terminal or intercalary on conidiophores and branches, determinate, cylindrical or subcylindrical, rounded at the apex and somewhat attenuated to the truncate end, with 1−2 inconspicuous conidiogenous loci.  Conidia 7−20 × 3.4−4.6 µm (x̄ = 15.1 × 3.9 µm, n = 10), acrogenous or acropleurogenous, cylindrical, subcylindrical or narrowly ellipsoidal, straight or somewhat flexuous, 1 to multiseptate, slightly constricted at some septa, smooth, verruculose, brown to reddish brown, formed in simple or branched, short acropetal chains of 2−4 conidia at conidiophores or branches, each conidium with 0−3 apical or lateral inconspicuous hila or 0−2 per individual conidial cell, apex rounded or slightly truncate, base truncate. Sexual morph: Unknown.

Material examined: United States, Florida, Collier, Vanderbelt Beach, on Serenoa repens (Arecaceae), 1 January 1978, JLC and JDS (ILL39688).