Thallus: squamulose, small to medium-sized, forming cushions 5-15 mm wide, squamules: peltate, irregularly cylindrical to flattened, rigid, 1-4(-6) mm tall, 1-2 mm wide lobes: (300-)350-550 µm thick, heteromerous, centrally with very loose hyphal strand incorporating a few photobiont cells, reticulate towards the lobe periphery, 60-80µm thick; with flattened and broadened lobe tips upper surface: black, ±smooth to rough or granulose and with some irregular folds lower surface: concolorous with the upper surface, dull, attached by central stalk and tufts of rhizohyphae Apothecia: thallinocarpous, filling the entire lobe tip or forming sublaminal to marginal, convex swellings, 0.3-0.6(-0.8) mm wide, ±round to irregularly shaped depending on the shape of the lobe tip disc: smooth or rough, when moistened somewhat paler than the sterile lobes; margin: thalline, up to 50 µm wide, indistinct; proper exciple: lacking hymenium: continuous, 75-110 µm tall, covered by ±continuous layer of sterile thalline tissue interruped by protruding asci, hymenium hyaline, IKI+ blue turning wine red; subhymenium: hyaline, continuous, IKI+ blue ascus: 16-24(-32)-spored ascospores: hyaline, simple, broadly ellipsoid to subglobose, small, 4-9 x 3-5 µm Pycnidia: not observed conidia: not observed Spot tests: all negative Secondary products: none detected. Substrate and ecology: on calcareous rock and caliche, rarely on (limeinfluenced) rhyolite World distribution: North America, SW Europe, NW Africa, and Sinai and Arabian Peninsulas Sonoran distribution: central and southern Arizona. Notes: Lichinella sinaica is characterized by small, squamulose-peltate thalli with erect, usually flattened lobules. The shape of the lobules is variable making the separation from the otherwise rather similar L. intermedia somewhat difficult. The former species seems to be restricted to limestone habitats in Arizona, whereas the latter is found on volcanic rock in Baja California. Furthermore, Lichinella sinaica usually has broader lobules with a very loose central strand.