 Spiny globular flower bud of a thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 10, 2012
 Thistle (Cirsium engelmannii) flower in Lick Creek Park. College Station, Texas, June 30, 2012
 Flower of thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 26, 2012
 Flower of thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2012
 Thistle (Cirsium engelmannii) flower bud in Lick Creek Park. College Station, Texas, June 10, 2012
 Close up of a flower of thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2012
 Thistle (Cirsium engelmannii) flower buds in Lick Creek Park. College Station, Texas, June 10, 2012
 Spiny flower bud of a thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 20, 2012
 Close up of a thistle (Cirsium engelmannii) flower bud in Lick Creek Park. College Station, Texas, June 10, 2012
 Thistle flower heads (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 7, 2012
 Blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 26, 2012
 Blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2012
 Thistle (Cirsium engelmannii) heads in Lick Creek Park. College Station, Texas, June 22, 2012
 Flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 13, 2022
 Flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2022
 Flower bud of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 13, 2022
 Flower of a thistle (Cirsium engelmannii(?)) near Deer Run Trail in Lick Creek Park. College Station, Texas, June 8, 2008
 Flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 27, 2022
 Unopened flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 13, 2022
 Opening flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2022
 Flower head of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2022
 Flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park, on Deer Run Trail. College Station, Texas, June 21, 2008
 Florets of a thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 7, 2012
 Thistle (Cirsium engelmannii) on sewage line right of way in Lick Creek Park. College Station, Texas, July 7, 2012
 Flower bud of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, March 31, 2024
 Flower bud of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 1, 2014
 Summer-blooming thistle flower (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 10, 2014
 Flower of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 1, 2014
 Flower bud of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 10, 2014
 Summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 22, 2022
 Summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 27, 2022
 Summer-blooming thistle flower (Cirsium engelmannii) from above in Lick Creek Park, on Iron Bridge Trail. College Station, July 6, 2008
 Summer-blooming thistle flower (Cirsium engelmannii) in Lick Creek Park, on Iron Bridge Trail. College Station, July 6, 2008
 Bumblebee on a summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, June 27, 2022
 Summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 3, 2014
 Summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 10, 2014
 Leaves of summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, March 12, 2024
 Blooming thistle (Cirsium engelmannii?) on Iron Bridge Trail in Lick Creek Park. College Station, Texas, July 30, 2008
 Seeds of summer-blooming thistle (Cirsium engelmannii) near Raccoon Run Trail in Lick Creek Park. College Station, Texas, July 22, 2020
 Blooming summer-blooming thistle (Cirsium engelmannii) in Lick Creek Park. College Station, Texas, July 3, 2014
 Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 11, 2018
 Flower of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
 Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 14, 2019
 Flower of yellow thistle (Bull thistle, Cirsium horridulum) with a bronze beetle in Lick Creek Park. College Station, Texas, April 5, 2019
 Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) on Post Oak Trail in Lick Creek Park. College Station, Texas, March 26, 2019
 Flower of thistle (Cirsium) in Lick Creek Park. College Station, Texas, August 4, 2021
 Yellow flower of bull thistle (Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 18, 2022
 Large flower bud of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Opening flower of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2018
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, March 31, 2024
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 6, 2022
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 18, 2022
 Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 12, 2024
 Blooming yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
 Seeds of yellow thistle (Bull thistle, Cirsium horridulum) on sewage line right-of-way in Lick Creek Park. College Station, Texas, May 2, 2023
 Yellow thistle (Bull thistle, Cirsium horridulum) on Post Oak Trail in Lick Creek Park. College Station, Texas, March 26, 2019
 Yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Rosette of leaves of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, January 10, 2024
 Yellow thistle (Bull thistle, Cirsium horridulum) on a recently built pipeline in Lick Creek Park. College Station, Texas, April 12, 2021
 Metallic beetles in yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline right-of-way in Lick Creek Park. College Station, Texas, April 12, 2021
 Fluffy seeds of yellow thistle (Bull thistle, Cirsium horridulum) on sewage line right-of-way in Lick Creek Park. College Station, Texas, May 2, 2023
 Arrangement of seeds of yellow thistle (Bull thistle, Cirsium horridulum) on sewage line right-of-way in Lick Creek Park. College Station, Texas, May 2, 2023
 Side view of a large yellow flower of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Winter rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 11, 2021
 Basal leaves of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
 Immature seed head of yellow thistle (Bull thistle, Cirsium horridulum) on sewage line right-of-way in Lick Creek Park. College Station, Texas, May 2, 2023
 Yellow thistle (Bull thistle, Cirsium horridulum) on a forest opening over a sewage line in Lick Creek Park. College Station, Texas, March 31, 2023
 Winter rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
 Summer-blooming thistles (Cirsium engelmannii) in Lick Creek Park, on Deer Run Trail. College Station, July 6, 2008
 Large thorny rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
 Rosette of thistle (Cirsium) in Lick Creek Park. College Station, Texas, February 27, 2023
 Fluffy seeds of thistle (Cirsium) in Lick Creek Park. College Station, Texas, May 20, 2014
 Fluffy seeds of thistle (Cirsium) in Lick Creek Park. College Station, Texas, August 1, 2021
 Thorny shoot of thistle (Cirsium) in Lick Creek Park. College Station, Texas, March 7, 2023
 Winter rosette of thistle (Cirsium) in dew in Lick Creek Park. College Station, Texas, January 23, 2023
 Thorny leaves of thistle (Cirsium) in Lick Creek Park. College Station, Texas, February 13, 2024
 Winter rosette of leaves of thistle (Cirsium) in Lick Creek Park. College Station, Texas, February 1, 2021
 Fluffy seeds of bull thistle (Cirsium horridulum) in Lick Creek Park. College Station, Texas, May 7, 2018
 Flower bud of a thistle on Iron Bridge in Lick Creek Park. College Station, Texas, June 8, 2010
 Winter rosette of bull thistle (Cirsium horridulum) with freeze in Lick Creek Park. College Station, Texas, January 3, 2022
 Leaf of a thistle (Cirsium) both in natural light and under 365 nm ultraviolet (UV-A) blacklight from Lick Creek Park. College Station, Texas, October 22, 2024
 Yellow flowers of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Opening thistle flower in Lick Creek park, on Iron Bridge Trail. College Station, June 15, 2008
 Emerging thistle flower in Lick Creek park, on Iron Bridge Trail. College Station, June 15, 2008
 Rosette and yellow flowers of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
 Leaves of bull thistle (Cirsium horridulum) in ultraviolet light on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Thistle (Cirsium engelmannii) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 12, 2018
 Globular flower of buttonbush (Cephalanthus occidentalis) near Nature Center in Lick Creek Park. College Station, Texas, August 1, 2021
 Rosette of basal leaves of bull thistle (Cirsium horridulum) in ultraviolet light on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Globular flower head of buttonbush (Cephalanthus occidentalis) near Nature Center in Lick Creek Park. College Station, Texas, July 11, 2020
 Thorny leaves of bull thistle (Cirsium horridulum) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Winter rosette of bull thistle (Cirsium horridulum) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Basal leaves of bull thistle (Cirsium horridulum) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Smaller rosette of basal leaves of bull thistle (Cirsium horridulum) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Central area of rosette of basal leaves of bull thistle (Cirsium horridulum) when exposed to regular daylight as well as when illuminated by a 365 nm ultraviolet (UV-A) blacklight on a sewage line right of way in Lick Creek Park. College Station, Texas, November 15, 2024
 Coreopsis flower in Lick Creek Park. College Station, Texas, June 6, 2012
 Winter rosette of leaves of some thistle (Cirsium) in Bee Creek Park. College Station, Texas, January 28, 2023
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