''Lepraria pacifica'', the Pacific dust lichen, is a whitish-blue-green leprosecrustose
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (locomotion), the surface over which an organism lo ...
like patches of granular, caked-up, mealy dust grains.A taxonomic revision of the North American species of ''Lepraria'' s.l. that produce divaricatic acid, with notes on the type species of the genus ''L. incana'', James C. Lendemer
, Mycologia 103(6): 1216–1229 /ref>Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Like other members of the ''
Lepraria
''Lepraria'' is a genus of leprose crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains.A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, with note ...
'' genus, it only reproduces asexually.
The main vegetative body ( thallus) is made of patches of soredia, little balls of algae wrapped in fungus. The thallus body may be discontinuous, starting off as isolated granules that divide to form aggregations that then merge to form a 0.1– 0.7 mm crust without a cortex (
ecorticate
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.pseudocortex. The photobiont consists of green
globose
A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the ce ...
coccoid
Coccoid means shaped like or resembling a coccus, that is, spherical.The noun coccoid or coccoids may refer to:
* a level of organization, characterized by unicellular, non-flagellated, non-amoeboid organisms, with a definite shape, in general b ...
cells. It produces a thick thallus and (usually) lacks
rhizohyphae
The following is a glossary of terms used in the description of lichens, composite organisms that arise from algae or cyanobacteria living among filaments of multiple fungus species in a mutualistic relationship.
Until the end of the 18th cen ...
and ascending thallus margins.
It is endemic to western North America. It grows on rock, soil, and bark, along the pacific coast of North America, from Coastal British Columbia to populations found in southern California, and in and near Yosemite National Park in the
Sierra Nevada
The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...
range. It is usually corticolous (grows on bark), and occurs only in western North America. It is usually found only growing on
conifer
Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...
s. In redwood forests, it is the most commonly found member of its genus. It is one of the only lichens that grows on the lower trunks of redwood trees. "Pacifica" refers to it being found only along the mountain ranges of the Pacific Coast in western North America, and in the
Sierra Nevada
The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...
Lichen spot test
A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change (or lack thereof) associated with application of the chemical ...
are K− or K+ purple, C ± pink, KC+ pink, P−, UV+ blue-white.
''Lepraria pacifica'' has a thallus similar in structure to some forms of the European '' L. incana'', but has a thicker thallus and always produces TLC detectable nordivaricatic acid. Its thick thallus is unlike other members of its genus, but this is variable. It is the only member of its genus that regularly produces divaricatic acid. It is characterized by having divaricatic acid,
zeorin
Zeorin is a triterpene with the molecular formula C30H52O2 which occurs in many lichens
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among hypha, filaments of multiple fungus, fungi species in a mutu ...
, and nordivaricatic acid, which is in lower concentrations than '' L. crassissima'' and '' L. cryophila''. It may be confused with ''L. crassissima'' and ''L. incana'' because of its similar chemistry, but it occurs in different biogeography and ecology. ''L. crassissima'' is mainly saxicolous (grows on rock), and is a European species with a thallus similar to ''L. cryophila'', with a well developed hypothallus and rhizohyphae as well as ascending thallus margins.