 Dry pad skeleton of prickly pears cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 13, 2020
 Skeleton of a dry pad of prickly pears cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2020
 Texture of a pad skeleton of prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Blooming prickly pears cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 30, 2011
 Dry pad skeleton of prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Dry skeleton of prickly peas cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 22, 2022
 Texture of a pad skeleton of prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Pads of prickly peas cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 25, 2018
 Pad of prickly pears (Opuntia) with a bug in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 22, 2022
 Yellow flowers of prickly pears (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 3, 2020
 Prickly peas cactus (Opuntia) with yellow Senecio(?) flowers in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 25, 2018
 Prickly pears (Opuntia) on exposed limestone rocks near a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 18, 2020
 Prickly peas (Opuntia cactus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 25, 2014
 Yellow flowers of Prickly pear cactus (Opuntia) in dew in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 19, 2012
 Purplish pads of a prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 28, 2023
 Rusty pads of prickly peas cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 22, 2022
 Vegetative shoot of prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Close-up of purple spots on pads of a prickly pear cactus (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 28, 2023
 Prickly pears in Washington-on-the-Brazos State Historic Site. Washington, Texas, October 16, 2011
 Pad of prickly pears in a forest in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 8, 2012
 Prickly pear (Opuntia) pad in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 10, 2011
 Prickly pear cacti (Opuntia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 27, 2019
 Pads of prickly pear cactus on Loop Trail in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 27, 2013
 Leaves of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Scaly stippled lichen (Endocarpon pusillum) on a thin layer of soil over exposed limestone rocks overgrown by prickly pears near a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 18, 2020
 Scaly stippled lichen (Endocarpon pusillum) on a thin layer of soil over exposed limestone rocks overgrown by prickly pears near a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 28, 2019
 Dark crust of scaly stippled lichen (Endocarpon pusillum) on a thin layer of soil over exposed limestone rocks overgrown by prickly pears in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 28, 2019
 Close-up of scaly stippled lichen (Endocarpon pusillum) on a thin layer of soil over exposed limestone rocks overgrown by prickly pears near a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 18, 2020
 Seedling of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 7, 2024
 Rosette of leaves of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 7, 2024
 Rosette of leaves of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 7, 2024
 White prickly poppy flower on field near Old Washington Town Site Loop Trail of Washington-on-the-Brazos State Historic Site. Washington, Texas, June 2, 2007
 Young leaves of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 6, 2023
 Prickly flower buds of bull nettle (Cnidoscolus texanus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 29, 2023
 White prickly poppy (Argemone albiflora) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight from Washington-on-the-Brazos State Historic Site. Washington, Texas, August 29, 2024
 Prickly flower buds on a shoot of bull nettle (Cnidoscolus texanus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 29, 2023
 Shoot of prickly pears cactus (Opuntia) in Antique Rose Emporium in Independence. Texas, March 22, 2009
 Prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 17, 2014
 Turtle skeleton and a half-rotten horse apple (osage orange) among leaves of hackberry in Washington-on-the-Brazos State Historic Site. Washington, Texas, October 20, 2012
 Prickly pear pad in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 10, 2011
 Leaves of prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 4, 2022
 White prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, August 9, 2008
 White flower of prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 9, 2009
 White prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, June 14, 2008
 Prickly poppy flower in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 27, 2008
 White prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2012
 White prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 13, 2008
 Flower of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 9, 2020
 Prickly pear cacti and dry trees in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 27, 2019
 Grasshopper on a white prickly poppy flower in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 24, 2009
 Prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Young katydid on white prickly poppy in Washington-on-the-Brazos State Historic Site. Washington, Texas, August 3, 2008
 White prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 21, 2018
 White prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 12, 2014
 White prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 12, 2018
 White prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2022
 White prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 19, 2012
 Prickly poppy flower with immature katydid in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 27, 2008
 White prickly poppy (Argemone albiflora) with a katydid in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 27, 2012
 Prickly seeds of Hedge Parsley (Torilis arvensis) in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 17, 2014
 Basal leaves of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 28, 2023
 Blooming white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2022
 Prickly flowers of Hooker s eryngo (Eryngium hookeri) in Washington-on-the-Brazos State Historic Site. Washington, Texas, June 16, 2019
 Flowers of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2022
 White prickly poppy (Argemone albiflora) with katidid in Washington-on-the-Brazos State Historic Site. Washington, Texas, August 10, 2019
 Young shoot of greenbrier vine (prickly-ivy, smilax, sarsaparilla) in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 9, 2009
 Prickly seeds of wild carrot (Daucus pusillus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, June 20, 2022
 Ovary of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 1, 2012
 Heart shaped leaf of greenbrier (prickly-ivy, smilax) in dew in Washington-on-the-Brazos State Historic Site. Washington, Texas, October 18, 2008
 Blooming white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 12, 2018
 Flower of prickly poppy (Argemone albiflora) with a beetle in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Bluebonnet (Lupinus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Pink phlox flowers in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Flower of bluebonnet (Lupinus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 26, 2024
 Small rosette of leaves of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 28, 2023
 Late blooming white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, July 2, 2022
 Prickly flower buds of bull nettle (Cnidoscolus texanus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 3, 2021
 Opening flower of white prickly poppy (pricklepoppy, Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 16, 2009
 Winter rosette of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 18, 2020
 Upper view of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2022
 Leaves with water drops of prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 28, 2023
 Close up of a green grasshopper sitting on a white prickly poppy flower in Washington-on-the-Brazos State Historic Site. Washington, Texas, May 24, 2009
 Winter rosette of white prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 11, 2023
 Prickly flow buds of bull nettle (Cnidoscolus texanus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 17, 2022
 Dark berries of greenbrier vine (prickly-ivy, smilax, sarsaparilla) in Washington-on-the-Brazos State Historic Site. Washington, Texas, October 18, 2008
 Bull nettle (Cnidoscolus texanus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 26, 2024
 Hairy leaves of bluebonnet (Lupinus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Tansy mustard (Descurainia pinnata) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 False dandelion (Pyrrhopappus carolinianus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Leaves of woolly-white (Hymenopappus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Gills of Psathyrella mushroom and cap of Pluteus in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Toad flax (Linaria texana) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Rosette of leaves of thistle (Cirsium) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Hover fly (syrphid) on a flower of w hite prickly poppy (Argemone albiflora) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 24, 2022
 Goldenhaired inkcap mushroom (Parasola auricoma) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 26, 2024
 Young leaves of red buckeye (Aesculus pavia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Prickleseed buttercup flowers (Ranunculus muricatus) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Flower buds of red buckeye (Aesculus pavia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
 Reddish shoot of red buckeye (Aesculus pavia) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 1, 2024
|