 View from a plane near Boulder. Colorado, July 15, 2007
 A field near Boulder, view from a plane. Colorado, July 21, 2007
 Macey Lake in Sangre de Cristo Mountains. Colorado, July 2, 2007
 Macey Falls in Sangre de Cristo Mountains. Colorado, July 2, 2007
 Lower Macey Lake in Sangre de Cristo Mountains. Colorado, July 2, 2007
 Southern Macey Lake in Sangre de Cristo Mountains. Colorado, July 2, 2007
 Near Macey Lakes Trail in Sangre de Cristo Mountains. Colorado, July 3, 2007
 View from a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Lower Macey Lake and Little Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 2, 2007
 Alpine tundra on a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 A dried tree on a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Crestone Peak from a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Alpine phlox(?) flowers on the slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Alpine primrose(?) (Primula angustifolia) on Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Hairy Androsace and deer clover on Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Sulphur flower buckwheat (Eriogonum umbellatum) on Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Calypso bulbosa (fairy slipper) orchid flowers near Macey Falls in Sangre de Cristo Mountains. Colorado, July 2, 2007
 A group of people from Dallas Sierra Club near Macey Lake Trail in Sangre de Cristo Mountains. Colorado, July 2, 2007
 A dead tree and Reiser Prairie from a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Rockslide daisy or Alpine aster(?) flower near southern Macey Lake in Sangre de Cristo Mountains. Colorado, July 2, 2007
 View of a slope of Colony Baldy Mountain from Macey Lakes Trail in Sangre de Cristo Mountains. Colorado, July 2, 2007
 People from Dallas Sierra Club west from Horn Creek Ranch in Sangre de Cristo Mountains. Colorado, July 1, 2007
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - views of Colorado and New Mexico from the bus 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 Dwarf alpine deer clover (Trifolium nanum) on Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Pink flowers of Moss campion (Silene acaulis) on Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Alpine Sandwort (Lidia obtusiloba, Minuartia biflora) on a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Alpine forget-me-not (Eritrichum aretioides) flowers carpeting the slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Dwarf cinquefoil and white alpine phlox wildflowers on a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 A creek on boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 A creek on boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 27, 2007
 In Chicago O Hare Airport. Illinois, August 7, 2007
 Skunk cabbage on boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 27, 2007
 Skunk cabbage on boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 A creek crossing on boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 27, 2007
 Airplane in O Hare Airport. Chicago, Illinois, September 11, 2007
 Escalator of O Hare Airport. Chicago, Illinois, September 11, 2007
 Umbrella-like May apple leaves near boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 27, 2007
 Leaves of skunk cabbage near boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 Leaves of skunk cabbage at morning near boulder field in John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 Boulder field near Devil s Cave near northern entrance of John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 Ceiling of Raphael Loggias in Hermitage museum. Saint Petersburg, Russia, August 14, 2007
 Dwarf sunflowers (Old-man-of-the-mountain, Rydbergia grandiflora, Hymenoxys grandiflora) on a slope of Colony Baldy Mountain in Sangre de Cristo Mountains. Colorado, July 3, 2007
 Morning mist on boulder field near Stuart Road entrance of John Witherspoon Woods park. Princeton, New Jersey, April 28, 2007
 Deeply divided umbrella-like young leaf of May apple near Boulder Field in John Witherspoon Woods park. Princeton, New Jersey, April 26, 2007
 Perspective view of airport escalators (moving sidewalks, or walkways) in Hamad International Airport. Doha, Qatar, September 17, 2015
 Hairy Androsace (Androsace villosa) alpine flowers on Colony Baldy Mountain in Sangre de Cristo Mountains, with white pinwheel-like flowers having a yellow "eye" that turns pink with age and tiny basal tightly clustered leaves. Colorado, July 3, 2007
 Aspens near Horn Creek trail in Sangre de Cristo Mountains. Colorado, June 30, 2007
 Junk cars, view from Road 50, near Airport Road. Brenham, Texas, June 2, 2007
 A meadow and aspens west from Horn Creek Ranch in Sangre de Cristo Mountains. Colorado, June 30, 2007
 Physcia lichen on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Grey crustose lichen Aspicilia on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Yellow map lichen (Rhizocarpon geographicum) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Rock shield lichen (Xanthoparmelia) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Rosette of yellow map lichen (Rhizocarpon geographicum) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Growth of yellow map lichen (Rhizocarpon geographicum) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 A terminal in Roissy-Charles de Gaulle Airport, Paris. July 8, 2003
 Ceiling of Majolica Room in Hermitage Museum. Saint Petersburg, Russia, July 22, 2005
 Windows of a terminal in Roissy-Charles de Gaulle Airport, Paris. July 8, 2003
 Atrium of Heydar Aliyev International airport. Baku, Azerbaijan, July 1, 2016
 Circular round patch of yellow map lichen (Rhizocarpon geographicum) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Pulkovo Airport, view from a window of a plane. Saint Petersburg, Russia, July 14, 2009
 Decorated ceiling of the Large Italian Skylight Hall in Hermitage Museum. Saint Petersburg, Russia, July 22, 2005
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - Alvarado Campground 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - Alvarado Campground 7/6/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - Goodwin lakes 7/5/97 (Colorado Mountains - Dallas, July 5 - 11, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 - dayhike near Goodwin lakes (Colorado Mountains, July 5, 1997)
 Close-up of crustose lichen Lecanora muralis (Protoparmeliopsis muralis) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Rosette of crustose lichen Lecanora muralis (Protoparmeliopsis muralis) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Elegant sunburst lichen Rusavskia elegans (formerly Xanthoria elegans) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Close-up of elegant sunburst lichen Rusavskia elegans (formerly Xanthoria elegans) on a granite boulder on shore of Gvardeysky Island. Vyborg, Russia, July 20, 2024
 Ceiling of Saint Isaac Cathedral. Saint Petersburg, Russia, July 4, 2003
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