Arsene's skin lichen
Leptogium arsenei
Description 4
Thallus: foliose, 2-5 cm in diam., adnate, subdichotomously to irregularly lobate; lobes: irregular, elongate, +plane to somewhat wrinkled, separate, 3-10 mm wide, 200-350(-500) µm thick; apices: rotund, entire to irregularly cut and isidiate, occasionally upturned; upper surface: usually medium gray but sometimes brownish gray, usually dull, wrinkled especially longitudinally; isidia: usually dense, laminal to marginal, granular initially, becoming cylindrical to sometimes lobulate, usually simple, concolorous with the thallus or darker; internal anatomy: with upper and lower cortices consisting of a single layer of irregularly isodiametrical cells 2-5 µm in diam., internally with loosely interwoven chains of Nostoc and hyphae; lower surface: pale to medium gray, wrinkled longitudinally, with scattered tufts of white hairs; Apothecia: not observed; Pycnidia: not observed; Spot tests: all negative; Secondary metabolites: none detected.; Substrate and ecology: particularly common on acidic rocks and occasionally found at the base of trees; World distribution: western to rarely central North America; Sonoran distribution: one of the most common Leptogiums on rock in central and southeastern Arizona, California, Baja California, Sonora and Chihuahua.; Notes: Darker thalli of L. arsenei are superficially rather like a Collema, due to its thick gelatinous thallus, but it has a proper cortex. Its granular isidia make it a distinctive species.
Fuentes y créditos
- (c) Sophia Lee, algunos derechos reservados (CC BY-NC-SA), https://collections.nmnh.si.edu/services/media.php?env=botany&irn=10546114
- (c) National Museum of Natural History Collections, algunos derechos reservados (CC BY-NC-SA), https://collections.nmnh.si.edu/services/media.php?env=botany&irn=10623888
- (c) Ingrid P. Lin, algunos derechos reservados (CC BY-NC-SA), https://collections.nmnh.si.edu/services/media.php?env=botany&irn=10623889
- (c) Lichen Unlimited: Arizona State University, Tempe., algunos derechos reservados (CC BY-NC-SA), http://eol.org/data_objects/10548280
