CONOTREMOPSIS ¹²

Gintaras Kantvilas ³

Conotremopsis Vĕzda, Folia Geobot. Phytotax. 12: 313 (1977).

Type: C. weberiana Vĕzda

Thallus byssoid. Photobiont Trentepohlia, with the cells in filaments 6–10 µm wide or subglobose, 10–20(–30) µm wide and occurring singly or in short chains, entwined by fungal hyphae c. 2 µm wide. Ascomata apothecia, minute, tubular or barrel-shaped, closed at first, when mature opening by a splitting of the apex of the proper exciple into dentate lobes. Disc plane to concave. Proper exciple carbonised, persistent, in section cupulate, opaque black-brown. Hypothecium hyaline. Hymenium hyaline, non-amyloid, I–, KI–, not inspersed. Asci very narrowly cylindrical, non-amyloid, 8-spored, with a thickened, KI– tholus and a thin, acute, ocular chamber. Paraphyses simple, with apices neither swollen nor pigmented. Ascospores filiform, indistinctly transversely 80–100-septate, hyaline, non-halonate, thin-walled. Conidiomata not known. Chemistry: nil.

A monotypic, epiphytic genus, known from wet forests in Tasmania, New Zealand and, remarkably, from Réunion. Together with Absconditella, Cryptodiscus and Ingvariella, Conotremopsis is included in the family Stictidaceae. It is distinguished from these genera by the barrel-shaped apothecia with a carbonised exciple, the extremely long, filiform, multi-septate ascospores, and by the Trentepohlia photobiont.

Key references: Vĕzda (1977); Kantvilas & Jarman (1999); Galloway (2007).

1 Conotremopsis weberiana Vĕzda

Folia Geobot. Phytotax. 12: 314 (1977). Type: Tasmania, Lake St Clair National Park, on saplings near shore of Lake St Clair at beginning of trail to Mt Hugel, 24 February 1968, W.A. Weber & D.N. McVean (holo—COLO; iso—BM!, CANB!, FH, HO!, LD, PRA-V, UPS, US).

Thallus fluffy, especially at the margins, dull pinkish orange to orange-green, fading to pale grey in storage, forming circular thalli to c. 10 cm wide. Apothecia superficial, basally constricted, 0.2–0.3 mm wide, 0.5–0.8 mm tall; proper exciple grey-black, covered by a thin weft of whitish hyphae, flaring and dentate at the apex with usually 5 triangular lobes, in section 25–50 µm thick, K–. Hymenium 500–600 µm thick; asci 430–500 × 8–10 µm; paraphyses c. 1 µm thick. Ascospores 80–100-septate, tightly coiled in the ascus, 400–420 × 2–2.5 µm.

Widespread in cool temperate rainforest, typically at higher elevations, where it occurs on the moderately dry sides of tree trunks, especially Nothofagus cunninghamii. The fluffy, orange-pink, circular thalli are unmistakable and grow directly on bark or overgrow bryophytes and other lichens. Although particularly common in the forests of the Great Western Tiers, Central Plateau and Cradle Mountain-Lake St Clair areas, Conotremopsis is widespread and extends southward to the Southern Ranges and westward to the Mt Murchison area. The minute, brittle, loosely attached apothecia make observation of the asci and ascospores very challenging, and the anatomical drawings of Vĕzda (1977) are exceptional.

Anthony Road, 41°50’S 145°38’E, 560 m, 1989, G. Kantvilas 10/89 (HO); track to Wylds Craig, 42°28’S 146°25’E, 880 m, 1998, G. Kantvilas 281/98 (HO); upper reaches of Little Fisher River, 41°46’S 146°20’E, 1000 m, 2012, G. Kantvilas 25/12 (distributed as Edit Farkas: Lichenes Delicati Exsiccati Editae: 37) (HO).

References