Slideshow image
Peltula tortuosa (Nees) Wetmore
Family: Peltulaceae
[Heppia tortuosa (Nyl.) Vain.]
Peltula tortuosa image
Thallus: suffruticose, often forming a tuff of aggregated thalli, lobate lobes: upright, flattened, somewhat branched, often twisted, occasionally partially terete, lobes up to 8 (-15) mm long and 0.4-1 mm wide at top upper surface: dark olive-brown to olive-green, smooth, not sorediate cortex: not developed in the upper part of the lobes but surrounded by a yellow-brown epinecral layer (5-12 µm thick), forming a rudimentary cortex (consisting of several layers of globose cells) at the base of the lobes medulla: paraplectenchymatous, composed of loosely interwoven hyphae with large air spaces, giving the impression of a hollow thallus lobes; algal layer: indistinctly delimited, scattered throughout lower surface: paler than the upper surface, attached by an umbilicus Apothecia: very rare, one the sides or in swollen ends of the lobes, several per lobe, immersed and punctiform; disc: slightly enlarging when mature; epihymenium: yellowish brown, K-; hymenium: I+ wine-red, >100-spored ascospores: globose to subglobose, 4.5 x 3-4.5 µm Pycnidia: immersed, spherical, on the sides or in swollen ends of lobes conidia: fusiform, 3.1-3.7 x 1.2 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on granitic rocks in deserts and other open, arid habitats World distribution: India, southern North America, Venezuela, and southern and tropical Africa Sonoran distribution: desert areas of Arizona, California.