TYPE. “Ad filices herbaceas montium altorum in Papeiti lectur a DD. Vieilard et Panchet. In insula Borbonia (coll. Lepervanche-Mezieres, n. 93, ex hb. Thuret, thallo altit. Semi-pollicari). Etiam in Brasilia, ex hb. Lenormand.” (Nylander 1858). TAHITI. Papiete, Vieielard & Panchet s.n. (H, leptotype designated by Henssen 1963).
Description.Life form: lichenized fungus.
Thallus fruticose, dark bluish-green or brownish, forming round cushions, +/- prostrate, shiny, densely and dichotomously branched, larger basal branches pale yellowish. Terminal branches smooth, 40-70 μm wide, lateral branches are smaller. Photobiont Scytonema cyanobacterium; cells in two rows. Ascomata biatorine apothecia, up to 2 mm diam.; disk reddish brown, flat to convex; margin subtending disk, pale. Exciple 80-200 μm, cells with thick, pitted walls; hymenium 80-60 μm high, I+ blue; subhymenium and hypothecium 100-160 μm thick. Paraphyses up to 2.5 μm thick, septate. Asci cylindrical, 65-70 x 9-12.5 μm, 8-spored uni- or biseriate; ascospores ovate to fusiform, hyaline, 1-2-septate, (11-)14-16(-20) x 5-7 μm. Conidiomata pycnidia, ~1 mm diam.; conidia 1.5-3.0 μm diam.
Chemistry. Not reported.
Substrate and Habitat. Corticolous on tree branches forests.
Distribution. Cosmopolitan; in North Carolina found in the Blue Ridge ecoregion.
Literature
Henssen, A. (1963) Eine Revision der Flechtenfamilien Lichinaceae und Ephebaceae. Symbolae Botanicae Upsalienses18: 1-123 (description as Polychidium dendrriscum).
Muggia L., P. Nelson, T. Wheeler, L.S. Yakovchenko, T. Tønsberg and T. Spribille (2011) Convergent evolution of a symbiotic duet: the case of the lichen genus Polychidium (Peltigerales, Ascomycota). American Journal of Botany 98: 1647–1656.
Nylander, W. (1858) Synopsis methodica Lichenum omnium hucusque cognitorum praemissa introductione lingua gallica tractata. L. Martinet, Paris. 140 pp (original description as Leptogium dendriscum).