![](../../pictures/archives/compress/2022/3127/jpeg/19t.jpg) Blooming bull thistle (Cirsium horridulum) on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2024/3510/jpeg/20t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on Richards Loop Trail in Sam Houston National Forest. Texas, April 13, 2024
![](../../pictures/archives/compress/2018/2242/jpeg/14t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on Lone Star Trail in Sam Houston National Forest, near Huntsville. Texas, April 8, 2018
![](../../pictures/archives/compress/2021/2904/jpeg/03t.jpg) Bull thistle (Cirsium horridulum) on a forest clearing on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, April 11, 2021
![](../../pictures/archives/compress/2022/3126/jpeg/20t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 6, 2022
![](../../pictures/archives/compress/2022/3134/jpeg/10t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 18, 2022
![](../../pictures/archives/compress/2022/3134/jpeg/11t.jpg) Yellow flower of bull thistle (Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 18, 2022
![](../../pictures/archives/compress/2018/2241/jpeg/17t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2018
![](../../pictures/archives/compress/2019/2478/jpeg/21t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
![](../../pictures/archives/compress/2024/3509/jpeg/24t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 12, 2024
![](../../pictures/archives/compress/2019/2478/jpeg/23t.jpg) Blooming yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
![](../../pictures/archives/compress/2019/2478/jpeg/22t.jpg) Flower of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 5, 2019
![](../../pictures/archives/compress/2018/2243/jpeg/14t.jpg) Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 11, 2018
![](../../pictures/archives/compress/2019/2482/jpeg/06t.jpg) Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, April 14, 2019
![](../../pictures/archives/compress/2021/2906/jpeg/12t.jpg) 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
![](../../pictures/archives/compress/2019/2477/jpeg/18t.jpg) Flower of yellow thistle (Bull thistle, Cirsium horridulum) with a bronze beetle in Lick Creek Park. College Station, Texas, April 5, 2019
![](../../pictures/archives/compress/2021/2906/jpeg/11t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on a recently built pipeline in Lick Creek Park. College Station, Texas, April 12, 2021
![](../../pictures/archives/compress/2022/3136/jpeg/12t.jpg) Thistle (Cirsium) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
![](../../pictures/archives/compress/2019/2473/jpeg/02t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on Post Oak Trail in Lick Creek Park. College Station, Texas, March 26, 2019
![](../../pictures/archives/compress/2019/2473/jpeg/01t.jpg) Flower bud of yellow thistle (Bull thistle, Cirsium horridulum) on Post Oak Trail in Lick Creek Park. College Station, Texas, March 26, 2019
![](../../pictures/archives/compress/2021/2919/jpeg/10t.jpg) Blooming yellow thistle (Bull thistle, Cirsium horridulum) in Bastrop State Park. Bastrop, Texas, April 25, 2021
![](../../pictures/archives/compress/2010/852/jpeg/10t.jpg) Yellow spiny thistle (Bull thistle, Cirsium horridulum) at sunrise in Lake Bryan Park. Bryan, Texas, April 13, 2010
![](../../pictures/archives/compress/2023/3374/jpeg/17t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on a forest opening over a sewage line in Lick Creek Park. College Station, Texas, March 31, 2023
![](../../pictures/archives/compress/2009/725/jpeg/09t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on Whitman Road, near Washington. Texas, March 22, 2009
![](../../pictures/archives/compress/2022/3096/jpeg/07t.jpg) Winter rosette of bull thistle (Cirsium horridulum) with freeze in Lick Creek Park. College Station, Texas, January 3, 2022
![](../../pictures/archives/compress/2024/3505/jpeg/14t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, March 31, 2024
![](../../pictures/archives/compress/2024/3458/jpeg/09t.jpg) Rosette of leaves of yellow thistle (Bull thistle, Cirsium horridulum) in Lick Creek Park. College Station, Texas, January 10, 2024
![](../../pictures/archives/compress/2021/2890/jpeg/21t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
![](../../pictures/archives/compress/2023/3402/jpeg/15t.jpg) Seeds of yellow thistle (Bull thistle, Cirsium horridulum) on sewage line right-of-way in Lick Creek Park. College Station, Texas, May 2, 2023
![](../../pictures/archives/compress/2023/3402/jpeg/18t.jpg) 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
![](../../pictures/archives/compress/2023/3402/jpeg/16t.jpg) 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
![](../../pictures/archives/compress/2021/2890/jpeg/25t.jpg) 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
![](../../pictures/archives/compress/2023/3402/jpeg/17t.jpg) 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
![](../../pictures/archives/compress/2021/2872/jpeg/03t.jpg) Basal leaves of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
![](../../pictures/archives/compress/2021/2879/jpeg/01t.jpg) Winter rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 11, 2021
![](../../pictures/archives/compress/2021/2872/jpeg/02t.jpg) Winter rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
![](../../pictures/archives/compress/2021/2872/jpeg/01t.jpg) Large thorny rosette of yellow thistle (Bull thistle, Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, February 25, 2021
![](../../pictures/archives/compress/2021/2919/jpeg/09t.jpg) Bull thistle (Cirsium horridulum) in Bastrop State Park. Bastrop, Texas, April 25, 2021
![](../../pictures/archives/compress/2022/3109/jpeg/11t.jpg) Leaves of bull thistle (Cirsium horridulum) in area of a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 20, 2022
![](../../pictures/archives/compress/2018/2236/jpeg/14t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum)(?) in Bastrop State Park. Bastrop, Texas, March 17, 2018
![](../../pictures/archives/compress/2010/845/jpeg/06t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum) in Lake Bryan Park. Bryan, Texas, March 20, 2010.
![](../../pictures/archives/compress/2022/3109/jpeg/12t.jpg) Rosette of leaves of bull thistle (Cirsium horridulum) in area of a former pond in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 20, 2022
![](../../pictures/archives/compress/2018/2236/jpeg/32t.jpg) Yellow thistle (Bull thistle, Cirsium horridulum)(?) on mulch in a tree utilization site in Bastrop State Park. Bastrop, Texas, March 17, 2018
![](../../pictures/archives/compress/2018/2257/jpeg/02t.jpg) Fluffy seeds of bull thistle (Cirsium horridulum) in Lick Creek Park. College Station, Texas, May 7, 2018
![](../../pictures/archives/compress/2020/2679/jpeg/01t.jpg) Bull thistle (Cirsium horridulum) at Lake Somerville Trailway near Birch Creek Unit of Somerville Lake State Park. Texas, April 5, 2020
![](../../pictures/archives/compress/2021/2890/jpeg/22t.jpg) Opening flower of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
![](../../pictures/archives/compress/2021/2890/jpeg/26t.jpg) Large flower bud of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
![](../../pictures/archives/compress/2021/2890/jpeg/23t.jpg) Yellow flowers of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
![](../../pictures/archives/compress/2021/2890/jpeg/24t.jpg) Rosette and yellow flowers of bull thistle (Cirsium horridulum) on a pipeline clearing in Lick Creek Park. College Station, Texas, March 24, 2021
![](../../pictures/archives/compress/2024/3642/jpeg/18t.jpg) 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
![](../../pictures/archives/compress/2021/2866/jpeg/06t.jpg) Bull thistle (Cirsium horridulum)(?) on a golf course on campus of Texas A and M University. College Station, Texas, February 14, 2021
![](../../pictures/archives/compress/2021/2866/jpeg/07t.jpg) Rosette of bull thistle (Cirsium horridulum)(?) on a golf course on campus of Texas A and M University. College Station, Texas, February 14, 2021
![](../../pictures/archives/compress/2021/2866/jpeg/11t.jpg) Icy rosettes of bull thistle (Cirsium horridulum)(?) on a golf course on campus of Texas A and M University. College Station, Texas, February 14, 2021
![](../../pictures/archives/compress/2024/3642/jpeg/17t.jpg) 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
![](../../pictures/archives/compress/2024/3642/jpeg/22t.jpg) 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
![](../../pictures/archives/compress/2024/3642/jpeg/16t.jpg) 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
![](../../pictures/archives/compress/2024/3642/jpeg/20t.jpg) 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
![](../../pictures/archives/compress/2024/3642/jpeg/21t.jpg) 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
![](../../pictures/archives/compress/2024/3642/jpeg/19t.jpg) 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
![](../../pictures/archives/compress/2024/3518/jpeg/01t.jpg) Bull nettle (Cnidoscolus texanus) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2024
![](../../pictures/archives/compress/2022/3172/jpeg/23t.jpg) Top view of a shoot of gayfeather (Liatris) at Forest Service Road 203 near Richards Loop Trail in Sam Houston National Forest. Texas, June 9, 2022
![](../../pictures/archives/compress/2022/3216/jpeg/07t.jpg) Side view of fibrecap (Inocybe) mushrooms on Richards Loop Trail in Sam Houston National Forest. Texas, August 25, 2022
![](../../pictures/archives/compress/2022/3216/jpeg/03t.jpg) Side view of white Amanita mushrooms under pines on Richards Loop Trail in Sam Houston National Forest. Texas, August 25, 2022
![](../../pictures/archives/compress/2022/3216/jpeg/19t.jpg) Side view of small pinkgill (Entoloma) mushrooms on Richards Loop Trail in Sam Houston National Forest. Texas, August 25, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/08t.jpg) Shoot of oak on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2018/2262/jpeg/01t.jpg) Rosette of leaves of thistle (Cirsium) in a pine forest on Caney Creek section of Lone Star Hiking Trail in Sam Houston National Forest near Huntsville, Texas, May 19, 2018
![](../../pictures/archives/compress/2022/3127/jpeg/23t.jpg) Shoot of sweetgum on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3127/jpeg/24t.jpg) Blooming hawthorn on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3127/jpeg/21t.jpg) Young leaves of oak on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/16t.jpg) Young leaves of an oak on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/14t.jpg) Shoot of beautyberry on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/05t.jpg) Blooming hawthorn on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/10t.jpg) Blooming dewberry on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2020/2681/jpeg/26t.jpg) Side view of Nolanea mushroom on Richards Loop Trail in Sam Houston National Forest. Texas, April 6, 2020
![](../../pictures/archives/compress/2020/2690/jpeg/05t.jpg) Side view of Amanita mushroom on Richards Loop Trail in Sam Houston National Forest. Texas, April 20, 2020
![](../../pictures/archives/compress/2022/3233/jpeg/04t.jpg) Side view of violet-gray bolete mushrooms Tylopilus plumbeoviolaceus on Richards Loop Trail in Sam Houston National Forest. Texas, September 7, 2022
![](../../pictures/archives/compress/2022/3211/jpeg/11t.jpg) Top view of peeling puffball mushroom (Lycoperdon marginatum) on a sandy track of FS 203 near Richards Loop Trail in Sam Houston National Forest. Texas, August 18, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/11t.jpg) Yellow Coreopsis flower on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/17t.jpg) Back lit young leaves of an oak on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/03t.jpg) Young leaves of beautyberry on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/09t.jpg) Back lit flowers of dewberry on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/12t.jpg) Pink phlox flower on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/02t.jpg) Young leaves of hickory on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2024/3518/jpeg/11t.jpg) Side view of white Amanita mushrooms on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2024
![](../../pictures/archives/compress/2020/2681/jpeg/30t.jpg) Side view of Clitocybula lacerata(?) mushrooms on Richards Loop Trail in Sam Houston National Forest. Texas, April 6, 2020
![](../../pictures/archives/compress/2022/3136/jpeg/05t.jpg) Woolly-white (Hymenopappus) on Forest Service Road 203 near Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
![](../../pictures/archives/compress/2022/3127/jpeg/22t.jpg) Rose vervain (Glandularia canadensis) on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/13t.jpg) Young leaf of mustang grape on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/18t.jpg) Red hairy shoot of mustang grape on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/01t.jpg) Paper mulberry (Broussonetia papyrifera)(?) on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/19t.jpg) Blue eyed grass (Sisyrinchium) on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3127/jpeg/20t.jpg) Reddish shoots of some common bush on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3127/jpeg/25t.jpg) Reddish shoot of mustang grape on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3136/jpeg/02t.jpg) Nodding beardtongue (Penstemon laxiflorus) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/07t.jpg) Reddish leaf of mustang grape on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3136/jpeg/04t.jpg) Green milkweed (Asclepias viridis) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
![](../../pictures/archives/compress/2022/3128/jpeg/21t.jpg) Racemed milkwort (Polygala polygama) on Richards Loop Trail in Sam Houston National Forest. Texas, April 9, 2022
![](../../pictures/archives/compress/2022/3136/jpeg/13t.jpg) Blooming poison ivy (Toxicodendron radicans) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
![](../../pictures/archives/compress/2022/3136/jpeg/10t.jpg) Flowers of woolly-white (Hymenopappus) on Richards Loop Trail in Sam Houston National Forest. Texas, April 21, 2022
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