The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified in December 2019 in Wuhan, China. The World Health Organization declared the outbreak a Public Health Emergency of International Concern on 20 January 2020, and later a pandemic on 11 March 2020. As of 28 March 2021, more than 126 million cases have been confirmed, with more than 2.77 million deaths attributed to COVID-19, making it one of the deadliest pandemics in history. Symptoms of COVID-19 are highly variable, ranging from none to life-threatening illness. The virus spreads mainly through the air when people are near each other. It leaves an infected person as they breathe, cough, sneeze, or speak and enters another person via their mouth, nose, or eyes. It may also spread via contaminated surfaces. People remain contagious for up to two weeks, and can spread the virus even if they are asymptomatic. Recommended preventive measures include social distancing, wearing face masks in public, ventilation and air-filtering, hand washing, covering one's mouth when sneezing or coughing, disinfecting surfaces, and monitoring and self-isolation for people exposed or symptomatic. Several vaccines are being developed and distributed. Current treatments focus on addressing symptoms while work is underway to develop therapeutic drugs that inhibit the virus. Authorities worldwide have responded by implementing travel restrictions, lockdowns, workplace hazard controls, and facility closures. Many places have also worked to increase testing capacity and trace contacts of the infected. The pandemic has resulted in significant global social and economic disruption, including the largest global recession since the Great Depression. It led to widespread supply shortages exacerbated by panic buying, agricultural disruption and food shortages, and decreased emissions of pollutants and greenhouse gases. Many educational institutions and public areas have been partially or fully closed, and many events have been cancelled or postponed. Misinformation has circulated through social media and mass media. The pandemic has raised issues of racial and geographic discrimination, health equity, and the balance between public health imperatives and individual rights.

Lepraria pacifica (Pacific dust lichen) is a whitish-blue-green leprose crustose lichen that grows on its substrate like patches of granular, caked-up, mealy dust grains. Like other members of the Lepraria genus, it only reproduces asexually. Lichen spot test are K− or K+ purple, C ± pink, KC+ pink, P−, UV+ blue-white.

The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified in December 2019 in Wuhan, China. The World Health Organization declared the outbreak a Public Health Emergency of International Concern on 20 January 2020, and later a pandemic on 11 March 2020. As of 28 March 2021, more than 126 million cases have been confirmed, with more than 2.77 million deaths attributed to COVID-19, making it one of the deadliest pandemics in history.

Lepraria pacifica (Pacific dust lichen) is a whitish-blue-green leprose crustose lichen that grows on its substrate like patches of granular, caked-up, mealy dust grains. Like other members of the Lepraria 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). It gradually forms an organized . The photobiont consists of green globose coccoid cells. It produces a thick thallus and (usually) lacks rhizohyphae 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 range. It is usually (grows on bark), and occurs only in western North America. It is usually found only growing on conifers. 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 range in and near Yosemite National Park. Lichen spot test 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 , 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 . It is characterized by having divaricatic acid, , and , which is in lower concentrations than and . 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.