 Cholla cactus (cylindropuntia) in Antique Rose Emporium. Independence, Texas, August 15, 2009
 Cane Cholla cactus and Southeast Rim, view from east part of Dodson Trail. Big Bend National Park, Texas, November 23, 2007
 Blooming cholla cactus(cylindropuntia) in TAMU Horticultural Gardens in Texas A and M University. College Station, Texas, April 26, 2012
 Switchbacks of Blue Creek Trail. Big Bend National Park, November 29, 2009
 Area of red rocks on Blue Creek Trail. Big Bend National Park, November 29, 2009
 One of eroded pinnacles of pink volcanic tuff on Blue Creek Trail. Big Bend National Park, November 29, 2009
 Fruits of Texas madrone (Arbutus xalapensis) on Blue Creek Trail. Big Bend National Park, November 29, 2009
 Eroded pinnacles of pink volcanic tuff looking like a miniature Bryce Canyon on Blue Creek Trail. Big Bend National Park, November 29, 2009
 Sandy washes of Blue Creek Canyon near Homer Wilson Ranch. Big Bend National Park, November 29, 2009
 Pitaya(?) cactus on Smokey Creek Trail east from Mule Ear Spring. Big Bend National Park, Texas, November 25, 2007
 Purple-tinged prickly pear cactus in the middle part of Smokey Creek Trail. Big Bend National Park, Texas, November 25, 2007
 Cactus on rocks of Smokey Creek. Big Bend National Park, Texas, November 25, 2007
 Purple-tinged prickly pear cactus on Smokey Creek Trail near Trap Spring east from Mule Ear Overlook. Big Bend National Park, Texas, November 25, 2007
 El Capitan Mountain with cholla cactus in foreground, view from upper Roadside Park. Guadalupe Mountains National Park, Texas, December 28, 2007
 Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) on Homestead Trail in McKinney Falls State Park. Austin, Texas, October 26, 2008
 Prickly pears cactus on a small ridge near Juniper Canyon Trail south from Upper Juniper Spring. Big Bend National Park, Texas, November 22, 2007
 Blue mould caused by fungus Penicillium italicum(?) on a fallen fruit of trifoliate orange on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, November 7, 2021
 Close-up of blue mould caused by fungus Penicillium italicum on a crashed fruit of trifoliate orange on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, November 18, 2023
 Blue mould caused by fungus Penicillium italicum on a fallen and crashed fruit of trifoliate orange on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, November 18, 2023
 Rotting fruit of trifoliate orange with blue and green mould caused by fungus Penicillium italicum(?) on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, November 7, 2021
 Boot Spring Trail. Big Bend National Park, November 26, 2009
 Emory Peak Trail in fog. Big Bend National Park, November 27, 2009
 Echinocactus horizonthalonius (devil s head cactus, or horse crippler) with daggerlike spines on a small ridge near Juniper Canyon Trail south from Upper Juniper Spring. Big Bend National Park, Texas, November 22, 2007
 Boot Canyon Trail ending at Southeast Rim. Big Bend National Park, November 27, 2009
 Upper section of Boot Canyon Trail. Big Bend National Park, November 27, 2009
 Slopes of Chisos Mountains from Pinnacles Trail. Big Bend National Park, November 26, 2009
 Upper part of Boot Canyon Trail. Big Bend National Park, November 27, 2009
 Tasajillo (Cylindropuntia) cactus taken from a fence at Road 322 south from Milano. College Station, Texas, December 2, 2012
 Christmas cactus (Tasajillo, Cylindropuntia leptocaulis) on a fence at Road 322 south from Milano. Texas, December 1, 2012
 Fall colors of Chisos Mountains from Pinnacles Trail. Big Bend National Park, November 26, 2009
 Emory Peak from lower section of Southwest Rim Trail. Big Bend National Park, November 28, 2009
 Slopes of Chisos Mountains from Boot Spring Trail. Big Bend National Park, November 26, 2009
 Cliffs of Toll Mountain from Boot Spring Trail. Big Bend National Park, November 26, 2009
 Century plant which bloomed, died, and tipped over, on Pinnacles Trail. Big Bend National Park, November 26, 2009
 Group of people with Dallas Sierra Club on Pinnacles Trail. Big Bend National Park, November 26, 2009
 Slopes of Chisos Mountains east from Boot Spring Trail. Big Bend National Park, November 27, 2009
 - Blue Creek Canyon (A trip to Big Bend Park, November 29 - 30, 1997)
 - Blue Creek Canyon (A trip to Big Bend Park, November 29 - 30, 1997)
 - Blue Creek Canyon (A trip to Big Bend Park, November 29 - 30, 1997)
 - Blue Creek Canyon (A trip to Big Bend Park, November 29 - 30, 1997)
 Cholla cactus in snow near a road between White s City and Carlsbad Caverns. New Mexico, December 26, 2007
 Southeast Rim in fog. Big Bend National Park, November 27, 2009
 Boot Rock from Boot Spring Trail. Big Bend National Park, November 28, 2009
 Boot Rock from Boot Spring Trail at sunrise. Big Bend National Park, November 28, 2009
 Boot Rock, view from Boot Spring Trail. Big Bend National Park, November 27, 2009
 View of Boot Rock from Boot Spring Trail. Big Bend National Park, November 27, 2009
 Dry tree on South Rim. Big Bend National Park, November 28, 2009
 Agaves on South Rim. Big Bend National Park, November 28, 2009
 Cliffs of South Rim. Big Bend National Park, November 28, 2009
 Dry juniper on South Rim. Big Bend National Park, November 28, 2009
 Casa Grande Peak of Chisos Mountains from Emory Peak Trail. Big Bend National Park, November 27, 2009
 Cacti and agaves on South Rim. Big Bend National Park, November 28, 2009
 Sunset from SW3 (Southwest Rim) campsite. Big Bend National Park, November 28, 2009
 Agaves on South Rim at sunrise. Big Bend National Park, November 29, 2009
 Pine tree on South Rim. Big Bend National Park, November 28, 2009
 Fall colors of Boot Canyon. Big Bend National Park, November 27, 2009
 Dry juniper tree on South Rim at morning. Big Bend National Park, November 29, 2009
 East summit of Emory Peak in fog. Big Bend National Park, November 27, 2009
 Upper part of Boot Canyon. Big Bend National Park, November 27, 2009
 Crooked pine on South Rim at morning. Big Bend National Park, November 29, 2009
 Crooked pine growing on South Rim. Big Bend National Park, November 28, 2009
 Elephant tusk Mountain from Southeast Rim. Big Bend National Park, November 28, 2009
 Paper-spined cholla cactus (Opuntia articulata) in Mercer Arboretum and Botanical Gardens. Humble (Houston area), Texas, July 18, 2014
 Paper-spined cholla cactus (Opuntia articulata) in Mercer Arboretum and Botanical Gardens. Humble (Houston area), Texas, July 20, 2013
 Most photographed spot with a pine tree on South Rim. Big Bend National Park, November 28, 2009
 Elephant Tusk Mountain from South Rim at sunrise. Big Bend National Park, November 29, 2009
 Rock-shield lichen Xanthoparmelia and a broken limb of Christmas cactus (Tasajillo, Cylindropuntia leptocaulis) in Enchanted Rock State Natural Area. Fredericksburg, Texas, December 25, 2018
 Flower of Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) in a ranch at 7278 Batts Ferry Road. College Station, Texas, August 1, 2014
 Flowers of Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) in a ranch at 7278 Batts Ferry Road. College Station, Texas, August 1, 2014
 Blooming Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) in a ranch at 7278 Batts Ferry Road. College Station, Texas, August 1, 2014
 Fruits of Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) in a ranch at 7278 Batts Ferry Road. College Station, Texas, August 1, 2014
 Gorman Falls (view from a trail) in Colorado Bend State Park. Bend, Texas, May 23, 2009
 Group of people with Dallas Sierra Club on Southeast Rim. Big Bend National Park, November 27, 2009
 Flower and fruits of Christmas cholla cactus (Tasajillo, Opuntia leptocaulis) in a ranch at 7278 Batts Ferry Road. College Station, Texas, August 1, 2014
 Blue heron bird near Pilant(?) Lake in Brazos Bend State Park. Needville, Texas, April 11, 2009
 Santa Elena Canyon and mountains in Mexico from SW3 (Southwest Rim) campsite at sunrise. Big Bend National Park, November 29, 2009
 Close up of blue mould caused by fungus Penicillium italicum on a fallen and rotting fruit of trifoliate orange on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, December 1, 2019
 Group of peole with Dallas Sierra Club watching sunset from SW3 (Southwest Rim) campsite. Big Bend National Park, November 28, 2009
 Agave on Smokey Creek Trail. Big Bend National Park, Texas, November 24, 2007
 Mule Ear Peaks from Smokey Creek Trail. Big Bend National Park, Texas, November 25, 2007
 Drooping juniper (Juniperus flaccida Var. flaccida) on Southeast Rim. Big Bend National Park, November 28, 2009
 East summit of Emory Peak, with north summit visible in fog. Big Bend National Park, November 27, 2009
 Smokey Creek Trail east from Mule Ear Spring. Big Bend National Park, Texas, November 25, 2007
 Smokey Creek Trail north from Mule Ear Peaks. Big Bend National Park, Texas, November 25, 2007
 Dallas Sierra Club on Smokey Creek Trail at rain. Big Bend National Park, Texas, November 24, 2007
 Ocotillo on Smokey Creek Trail north from Mule Ear Peaks. Big Bend National Park, Texas, November 25, 2007
 Bee Mountain, view to the west from Smokey Creek Trail near Mule Ear Spring. Big Bend National Park, Texas, November 25, 2007
 Desert mistletoe(?) growing on ocotillo, view from Smokey Creek Trail. Big Bend National Park, Texas, November 25, 2007
 Blue mould caused by fungus Penicillium italicum on a fallen fruit of trifoliate orange on Caney Creek section of Lone Star Hiking Trail in Sam Houston National Forest north from Montgomery. Texas, December 29, 2021
 Blue mould caused by fungus Penicillium italicum on a rotting fruit of trifoliate orange on Caney Creek section of Lone Star Hiking Trail in Sam Houston National Forest north from Montgomery. Texas, December 28, 2020
 Valley of Smokey Creek, view to the east from a trail north from Mule Ear Peaks. Big Bend National Park, Texas, November 25, 2007
 Goat Mountain, view to the north from Smokey Creek Trail near Mule Ear Spring. Big Bend National Park, Texas, November 25, 2007
 Smokey Creek Trail through creosote bushes and cacti east from Mule Ear Overlook. Big Bend National Park, Texas, November 25, 2007
 Close-up of blue mould caused by fungus Penicillium italicum on a fallen fruit of trifoliate orange on Caney Creek section of Lone Star Hiking Trail in Sam Houston National Forest north from Montgomery. Texas, December 29, 2021
 Blue mould caused by fungus Penicillium italicum on a fallen and rotting fruit of trifoliate orange in area of Caney Creek crossing on Lone Star Hiking Trail in Sam Houston National Forest near Huntsville, Texas, February 9, 2020
 Fallen fruit of sweetgum (Liquidambar styraciflua) on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, November 16, 2019
 Spicewood Springs in Colorado Bend State Park. Bend, Texas, May 23, 2009
 Gorman Falls in Colorado Bend State Park. Bend, Texas, May 23, 2009
 Under Gorman Falls in Colorado Bend State Park. Bend, Texas, May 23, 2009
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