Niebla homaleoides
Niebla homaleoides is a fruticose lichen that grows on rocks within a narrow region of the foggy Pacific Coast of Baja California in the Northern Vizcaíno Desert, Arroyo Sauces, Punta Cono and ridges south of Punta Negra. The epithet, homaleoides is in reference to the similarity to Niebla homalea.
Distinguishing features
Niebla homaleoides is characterized by a rigid thallus divided into sub mostly strap-shaped branches spreading from a holdfast, to 8 cm high, and by the absence of lichen substances except usnic acid and an unknown suspected to be a scabrosin derivative. The species is best identified by chromatography such as high-performance liquid chromatography or thin-layer chromatography. The cortex generally resembles that of Niebla cornea, whereas comb-like branchlets on some thalli are similar to those of Niebla josecuervoi. Other thalli that have flattened branches are similar to Niebla flabellata. Pycnidia are prominent on the upper parts of branches, and appear to be among the largest in the genus, but comparative measurements are not available for all species of Niebla.Niebla homaleoides is related to the depsidone species within the genus by the absence of triterpenes, most closely to salazinic acid-containing species by the presence of an unknown, possibly scabrosin derivative. This lichen chemotype is found in the related Niebla flabellata, Niebla josecuervoi, and Niebla marinii. Scabrosin esters isolated from the lichen Xanthoparmelia scabrosa have shown activity against human tumor cell lines at nanomolar concentrations.