Duradens lignicola Samuels & Rogerson

  • Authority

    Samuels, Gary J. & Rogerson, Clark T. 1990. New ascomycetes from the Guayana Highland. Mem. New York Bot. Gard. 64: 165-183.

  • Family

    Clypeosphaeriaceae

  • Scientific Name

    Duradens lignicola Samuels & Rogerson

  • Description

    Species Description - Ascomata conica, 1.5-2 mm longa, 1-1.5 mm lata, 1-2 mm alta, nigra, basim immersi, apice acuta; murus ascomatis 300-500 µm latis, carbonaceis. Asci cylindrici vel anguste clavati, 300- 450 X 17.5-25 µm, apice annulo refractili, nonchitinoideo, iodo noncoerulescenti provisi. Ascosporae filiformes vel anguste clavatae, 140- 172 X 7.5-10 µm, eseptatae vel pauciseptatae. Paraphyses simplici, septati, ad apicem liberi. Status anamorphicus ignotis. Ascomata conical, laterally compressed, 1.5- 2 mm long, 1-1.5 mm wide, 1-2 mm high, with an acute apex, black, immersed, becoming erumpent through decorticated wood with fragments of wood adherent to the ascomatal wall, gregarious, not collapsed when dry. Ascomatal wall 300-500 ixm thick above, very thin below, completely carbonized and individual cells not visible; ascomatal opening not observed, ascomatal

    Distribution and Ecology - Guyana, known orUy from the type collection.

  • Discussion

    Hab.: In ligno decorticato. Holotypus: Guyana (Samuels 6532, N Y ). Anamorph: None known

    Habitat. Decorticated wood suspended above running water.

    Notes. We do not see close relatives for Duradens. The very thick, carbonized ascomatal waU that can only be chipped away with the tip of a scalpel is unusual. W e have seen it previously only in the loculoascomycete, Trematosphaeria perrumpens Samuels & Muller (Samuels & Muller, 1978), a species that is superficially indistinguishable from Duradens lignicola. This hard upper wall is comparable to, but more strongly developed than, the stromatic thickening over the ascomatal apex in Melomastia Nitschke ex Sacc. of the Clypeosphaeriaceae {sensu Barr, in litt.). The filiform ascospores are suggestive of the Lasiosphaeriaceae, but the ascal apex is more like that found in genera of the Clypeosphaeriaceae. The combined characters of a thick, carbonaceous upper ascomatal wall and a large, nonamyloid apical ring in the asci lead us to refer Duradens to the Clypeosphaeriaceae of the Xylariales (sensu Barr, in litt.). W e were not able to determine how the ascomata open. There is an obviously thin area or ostiolar canal in the inside ofthe ascomatal wall at the apex (Fig. 24), but we could not see an opening to the exterior