Macentina Vězda
Type : Macentina perminuta Vězda
Description : Thallus crustose or minutely filamentous; hyphae smooth or papillose. Photobiont green, chlorococcoid. Ascomata perithecia, pale-brown, surface naked or rarely with a ring-shaped collar. Involucrellum absent. Exciple pale, of periclinally arranged elongated cells, sometime with a surface layer of isodiametric cells. Hamathecium of periphyses; paraphyses absent. Asci 8-spored; fissitunicate, clavate–cylindrical, thickened at apex when young, I−. Ascospores 12–26 × 3.5–5 μm, transversely (1–)3-septate to submuriform, elongate–ellipsoidal, smooth, without a perispore, colourless. Conidiomata unknown. Chemistry negative.
Macentina, originally described for a foliicolous lichen from West Africa (Vězda 1973), is a genus of seven described species included in the family Verrucariaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) including foliicolous, corticolous and lignicolous taxa (Coppins & Vězda 1977; Döbbeler & Vězda 1982; Farkas & Vězda 1987, 1993; Orange 1989a, 1989b, 1991a, 1992a; Kalb & Vězda 1992). Macentina is characterised by: a crustose or minutely filamentous thallus; pale-brown perithecia, lacking an involucrellum and with a pale-brown, not carbonised exciple; a hamathecium of periphyses; and (1–)3-septate to submuriform, colourless ascospores. Two species occur on shaded bark in temperate Europe, with the remainder being foliicolous species from tropical Africa and Brazil. A key to species is given in Orange (1991). Kalb & Hafellner (1992) synonymised Macentina with Leucocarpia Vězda (Vězda 1969b) a position accepted by Nimis (1993) and by Santesson (1993). One of the European species was recently identified from a New Zealand collection.
