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Niebla and Vermilacinia (Ramalinaceae)
from California and Baja California. |
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Niebla versiforma is a lichen that is endemic to northern Baja California, known only from a single (type) collection from a lava mesa above San Antonio del Mar. It was found growing with other species of Niebla on rubble among larger lava rock in a low mixed succulent-thorn scrub of Rosa minutifolia, Dudleya ingens, Agave shawei, Eriogonum fastigiatum, Frankenia palmeri, Echinocereus maritima, Ferocactus fordii and Mammillaria dioica. The low vegetation, not more than waist-high, formed an impenetrable thicket. During the 1980's species of Niebla and other lichens were observed mostly on the emergent rocks and on the gravel substrate near the edge of the mesa along a road west of Mexican Highway 1 that led to San Antonio del Mar. The lichens were not easily accessible due to the nearly continuous ground cover of Mammillaria dioica among the taller spiny shrubs and other cacti. One had to walk on Mammillaria to reach the lichens, a discouraging and nasty barrier. By 1990 many cacti had disappeared (obviously removed by cactus collectors). Consequently, lichens became easier to study. Niebla versiforma was then discovered on the mesa among other species of Niebla that included the terricolous N. arenaria, N. effusa, N. juncosa var. spinulifera, N. pulchribarbara, and saxicolous N. fimbriata and N. josecuervoi. Niebla versiforma is distinct for its bush-like growth of intricately divided contorted branches in combination with the lichen substance divaricatic acid (with triterpenes). It is distinguished from the related divaricatic-acid N. juncosa var. spinulifera by the upper dilated branches giving rise to digitate-like arrangement of fringing branchlets as seen in N. effusa, which differs by its lichen substance of salazinic acid. One cannot help but wonder if N. versiforma is a product of hybridization between N. effusa and N. juncosa (or N. palmeri) since these species also occurred in the same habitat. On Mesa Camacho, north of Punta Canoas, are unique forms of N. marinii (salazinic acid) and N. suffnessii (sekikaic acid), characterized by sharply raised sinuous cortical ridges, a character trait not seen in other species. While they differ by their secondary metabolites as indicated, a third species also seems involved, N. turgida, recognized by having divaricatic acid and sharply defined vein-like cortical ridges on upper branchlets. Another putative 'threesome hybrid' complex is mentioned for N. homaleoides
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