Pleosporales » Lophiostomataceae » Lophiostoma

Lophiostoma frondisubmersum

Lophiostoma frondisubmersum (K.D. Hyde) E.C.Y. Liew, Aptroot & K.D. Hyde

Basionym: Massarina fronsisubmersa K.D. Hyde, Mycol. Res. 98(7): 724 (1994)

Index Fungorum number: IF 534445

Holotype: BRIP 21393

Etymology: From the Latin frons meaning' frond' and submersus meaning 'growing under water' in reference to the habitat of this taxon.


Sexual morph: Ascomata immersed under raised conical regions on the host surface, with a central slot-like ostiole, solitary or gregarious; in horizontal section globose; in vertical section 185390 μm diam., 180300 μm high, conical or hemispherical with a flattened base, papilla erumpent, with a wedge of vertically orientated hyaline palisade-like cells at the periphery, between the base and sides. Peridium up to 40 μm thick at the sides, composed of an inner layer of compressed hyaline thin-walled cells and an outer layer comprising host cells, filled with brown fungal hyphae of textura intricata; base to 30 μm thick, comprising several layers of compressed thin-walled hyaline, irregular cells. Base and side with variable stromatal development, comprising host cells and brown fungal hyphae. Papilla up to 200 μm high and 150 μm diam., erumpent slot-like, composed of small pigmented angular cells. Pseudoparaphyses ca 2 μm diam., hyphalike, filamentous, numerous, sheet-like, cellular, septate, hyaline, embedded in a gelatinous matrix. Asci 86102 × 11–14 μm, 8-spored, cylindric-clavate, pedunculate, bitunicate, fissitunicate, apically rounded, with an ocular chamber and faint ring. Ascospores 2328 × 47 μm, 2-seriate, fusiform, hyaline, 2-celled, constricted at the central septum, with apically somewhat acute poles bearing appendages 818 μm long, 24 μm wide, with an inner canal-like region appearing as an inner apical spine. Asexual morph: Undetermined. (Descriptions from Hyde 1994)


Material examined: PAPUA NEW GUINEA, Western Province, Bensbach, Bensbach River, on submerged rachides of Livistona sp., May 1992, K. D. Hyde 1392, BRIP 21393.


Notes: Massarina fronsisubmersa was transferred to Lophiostoma with fusiform spores, previously undoubtedly placed in Massarina, thus widening the circumscription of Lophiostoma to encompass not only taxa with slot-like ostioles, but also with punctiform ostioles. (Notes from Liew et al. 2002)


Freshwater distribution: New Guinea, USA




Fig. 1 Lophiostoma frondisubmersum 27, 28 Ascomata on host surface. Note the slot-like neck. 29, 30 Sections through ascomata. Note the applanate base. 31 Upper wall comprising inner layer of compressed cells and outer host cells with intercellular fungal hyphae. 32 Wedge of palisade-like cells at periphery of ascoma. 33 Upper peridium. 34 Lower peridium. Scale bars = 100 μm. (Hyde 1994)