 Yellow wood sorrel (Oxalis stricta) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2020
 Flowers of yellow wood sorrel (Oxalis stricta) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2020
 Yellow wood sorrel (shamrock, Oxalis dillenii?) on Richards Loop Trail in Sam Houston National Forest. Texas, March 30, 2024
 Blooming yellow wood sorrel (shamrock, Oxalis dillenii?) on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, March 29, 2009
 Violet wood sorrel (shamrock, Oxalis violacea) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2020
 Violet wood sorrel (shamrock, Oxalis violacea) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Yellow wood sorrel (shamrock, Oxalis dillenii?) in Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, May 26, 2012
 Blooming yellow wood sorrel (shamrock, Oxalis dillenii?) on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 13, 2012
 Yellow flower of wood sorrel (shamrock, Oxalis dillenii?) on Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 13, 2012
 Violet wood sorrel (Oxalis violacea) on Richards Loop Trail in Sam Houston National Forest. Texas, March 3, 2024
 Common yellow wood sorrel (Oxalis stricta) on Lost Pines Trail in Bastrop State Park. Bastrop, Texas, March 14, 2019
 Blooming common yellow wood sorrel (Oxalis stricta) on Lost Pines Trail in Bastrop State Park. Bastrop, Texas, March 14, 2019
 Yellow flowers of common wood sorrel (Oxalis stricta) on Lost Pines Trail in Bastrop State Park. Bastrop, Texas, March 14, 2019
 Sorrel rust fungus (Puccinia oxalidis) on yellow oxalis (Oxalis stricta) in wet area on Raccoon Run Trail in Lick Creek Park. College Station, Texas, March 26, 2019
 Close up of yellow flowers of common wood sorrel (Oxalis stricta) on Lost Pines Trail in Bastrop State Park. Bastrop, Texas, March 14, 2019
 Common yellow oxalis (Oxalis stricta) with sorrel rust fungus (Puccinia oxalidis) in wet area on Raccoon Run Trail in Lick Creek Park. College Station, Texas, March 26, 2019
 Common yellow oxalis (Oxalis stricta) with sorrel rust fungus (Puccinia oxalidis) in wet area on Raccoon Run Trail in Lick Creek Park. College Station, Texas, March 22, 2019
 Leaves of yellow oxalis (Oxalis stricta) with sorrel rust fungus (Puccinia oxalidis) in wet area on Raccoon Run Trail in Lick Creek Park. College Station, Texas, March 26, 2019
 Sorrel rust fungus (Puccinia oxalidis) on yellow oxalis (Oxalis stricta) in Bee Creek Park. College Station, Texas, March 29, 2022
 Flower of Violet Wood Sorrel (Oxalis violacea) in Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 22, 2011
 Flowers of Violet Wood Sorrel (Oxalis violacea) in Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 22, 2011
 Back lit Violet Wood Sorrel (Oxalis violacea) in Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 22, 2011
 Violet Wood Sorrel (Oxalis violacea) blooming at fall without leaves in Little Lake Creek Loop Trail in Sam Houston National Forest. Richards, Texas, October 22, 2011
 Violet wood sorrel (Oxalis violacea) both in natural light and under 365 nm ultraviolet (UV-A) blacklight from Richards Loop Trail in Sam Houston National Forest near Montgomery. Texas, September 6, 2024
 Underside of leaves of wood sorrel Oxalis stricta with rust fungus Puccinia oxalidis in Bee Creek Park. College Station, Texas, March 29, 2022
 Blooming yellow wood sorrel (shamrock, Oxalis dillenii?) with soldier flies (Stratiomyidae) in Big Thicket park on Sandhill Loop Trail. Texas, March 23, 2008
 Violet wood sorrel (Oxalis violacea) on Lone Star Hiking Trail in Sam Houston National Forest west from Richards. Texas, April 9, 2019
 Flower of violet wood sorrel (Oxalis violacea) on Lone Star Hiking Trail in Sam Houston National Forest west from Richards. Texas, April 9, 2019
 Yellow wood sorrel (Oxalis) near Pole Creek on North Wilderness Trail of Little Lake Creek Wilderness in Sam Houston National Forest north from Montgomery. Texas, March 26, 2022
 Flowers of yellow wood sorrel (Oxalis) near Pole Creek on North Wilderness Trail of Little Lake Creek Wilderness in Sam Houston National Forest north from Montgomery. Texas, March 26, 2022
 Blooming slender trillium (Trillium gracile) and yellow wood sorrel (Oxalis) on Fringe Tree Trail in Little Thicket Nature Sanctuary. Cleveland, Texas, March 23, 2024
 Pink flowers of wood sorrel (Oxalis) on Stubblefield section of Lone Star hiking trail north from Trailhead No. 6 in Sam Houston National Forest. Texas, April 2, 2022
 Spiderwort (Tradescantia) and yellow wood sorrel (oxalis) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 6, 2022
 Back-lit purple flower of wood sorrel in Sam Houston National Forest on Little Lake Creek Loop Trail. Richards, Texas, April 4, 2010.
 Violet wood sorrel (Oxalis violacea, shamrock) on Hoots Hollow Trail in Brazos Bend State Park. Needville, Texas, February 15, 2020
 Pink flowers of Violet wood sorrel (Oxalis violacea, shamrock) on Hoots Hollow Trail in Brazos Bend State Park. Needville, Texas, February 15, 2020
 Violet wood sorrel (Oxalis violacea) on Sundew Trail in Big Thicket National Preserve. Kountze, Texas, August 2, 2014
 Yellow woodsorrel (Oxalis stricta) in Washington-on-the-Brazos State Historic Site. Washington, Texas, March 9, 2019
 Bloomin violet wood sorrel (Oxalis violacea, shamrock) in Little Thicket Nature Sanctuary. Cleveland, Texas, March 25, 2023
 Flowers of violet wood sorrel (Oxalis violacea, shamrock) in Little Thicket Nature Sanctuary. Cleveland, Texas, March 25, 2023
 Yellow flower of rock-rose (frostweed, sunrose, Helianthemum carolinianum) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2020
 Back lit flowers of violet wood sorrel (Oxalis violacea, shamrock) in Little Thicket Nature Sanctuary. Cleveland, Texas, March 25, 2023
 Pink flowers of violet wood sorrel (Oxalis violacea, shamrock) in Little Thicket Nature Sanctuary. Cleveland, Texas, March 25, 2023
 Violet wood sorrel (shamrock, Oxalis violacea?) in Big Thicket park on Sundew Trail. Texas, October 11, 2008
 Wood sorrel (Oxalis acetosella, Kislitsa in Russian) carpeting a forest in Lomonosov (Oranienbaum). West from Saint Petersburg, Russia, May 23, 2011
 Pink wood sorrel (shamrock, Oxalis violacea?) in Mercer Arboretum and Botanical Gardens. Humble (Houston area), Texas, February 8, 2009
 Violet wood sorrel (shamrock, Oxalis violacea?) in Mercer Arboretum and Botanical Gardens. Humble (Houston area), Texas, April 5, 2009
 Orange-yellow rust fungus Puccinia poarum (Puccinia liatridis) on a leaf of gayfeather (Liatris) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Orange-yellow rust fungus Puccinia poarum (Puccinia liatridis) on basal leaves of gayfeather (Liatris) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Basal leaves of gayfeather (Liatris) with orange-yellow rust fungus Puccinia poarum (Puccinia liatridis) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Yellow leaves of hickory on Richards Loop Trail in Sam Houston National Forest. Texas, December 15, 2020
 Close-up of orange-yellow rust fungus Puccinia poarum (Puccinia liatridis) on basal leaves of gayfeather (Liatris) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Underside of basal leaves of gayfeather (Liatris) with orange-yellow rust fungus Puccinia poarum (Puccinia liatridis) on Richards Loop Trail in Sam Houston National Forest. Texas, March 26, 2020
 Pink flower of Violet wood sorrel (Oxalis violacea, shamrock) on Prairie Trail in Brazos Bend State Park. Needville, Texas, April 22, 2008
 Tiny purple flower of Violet wood sorrel (shamrock, Oxalis) on Deer Run Trail in Lick Creek Park. College Station, Texas, September 30, 2008
 Yellow web-like corticioid fungus under a pine(?) log on Richards Loop Trail in Sam Houston National Forest. Texas, December 24, 2020
 Cap some pale yellow Amanita mushroom on Richards Loop Trail in Sam Houston National Forest. Texas, June 3, 2020
 Tiny yellow flowers of Hypericum(?) on Richards Loop Trail in Sam Houston National Forest. Texas, July 28, 2020
 Candlesnuff fungus (Xylaria hypoxylon) on rotting wood on Richards Loop Trail in Sam Houston National Forest. Texas, April 20, 2020
 Details of yellow web-like corticioid fungus under a pine(?) log on Richards Loop Trail in Sam Houston National Forest. Texas, December 24, 2020
 Gills of blusher mushrooms (Amanita amerirubescens)(?) on rotting wood on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Tiny white slime mold (Eumycetozoa) on rotting wood on Richards Loop Trail in Sam Houston National Forest. Texas, April 11, 2020
 Yellow woodsorrel (Oxalis stricta) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 13, 2021
 Dissected view of some pale yellow Amanita mushroom on Richards Loop Trail in Sam Houston National Forest. Texas, June 3, 2020
 Side view of some pale yellow Amanita mushroom on Richards Loop Trail in Sam Houston National Forest. Texas, June 3, 2020
 Some dark red mature bolete mushrooms with yellow pores on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Common rustgill mushrooms (Gymnopilus penetrans) on rotting pine wood on Richards Loop Trail in Sam Houston National Forest. Texas, December 15, 2020
 Yellow flowers of sunflower family on Richards Loop Trail in Sam Houston National Forest. Texas, March 30, 2024
 Flowers of yellow woodsorrel (Oxalis stricta) in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 13, 2021
 Wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 20, 2017
 Wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 10, 2016
 Violet woodsorrel (Oxalis violacea) on Lone Star Hiking Trail near Pole Creek in Sam Houston National Forest. Richards, Texas, March 1, 2019
 Underside of dark red mature bolete mushrooms with yellow pores on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Yellow flower of St. Peter s-wort (Hypericum crux-andreae) on Richards Loop Trail in Sam Houston National Forest. Texas, July 28, 2020
 Yellow underside of pineapple bolete mushroom (Boletellus ananas) on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Yellow woodsorrel (Oxalis stricta) on a sandy path in Washington-on-the-Brazos State Historic Site. Washington, Texas, April 13, 2021
 Immature pinewood gingertail mushrooms (Xeromphalina campanella) on rotting pine wood on Richards Loop Trail in Sam Houston National Forest. Texas, December 24, 2020
 Yellow star-grass (Hypoxis hirsuta) on Richards Loop Trail in Sam Houston National Forest. Texas, March 3, 2024
 Wood sorrel (Oxalis acetosella, Russian name Kislitsa) with flowers in Sosnovka Park. Saint Petersburg, Russia, May 20, 2017
 Flower of wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 20, 2017
 Blooming wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 20, 2017
 Flowers of wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 10, 2016
 Wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Tarkhovka near Sestroretsk. West from Saint Petersburg, Russia, May 13, 2019
 Blooming wood sorrel (Oxalis acetosella, Russian name Kislitsa) in Sosnovka Park. Saint Petersburg, Russia, May 10, 2016
 Wood sorrel (Oxalis acetosella, Russian name Kislitsa) in flower in Sosnovka Park. Saint Petersburg, Russia, May 20, 2017
 Leaves of violet woodsorrel (Oxalis violacea) on Lone Star Hiking Trail near Pole Creek in Sam Houston National Forest. Richards, Texas, March 1, 2019
 Yellow corticioid mushroom Botryobasidium robustius or may be B. aureum on rotting oak wood on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest north from Montgomery. Texas, June 13, 2020
 Yellow leaf of passion flower (Passiflora lutea) on Sand Branch Loop Trail in Sam Houston National Forest near Richards. Texas, November 20, 2020
 Yellow powdery bolete mushroom (Buchwaldoboletus hemichrysus) near a pine stump on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Cross section of dark red mature bolete mushrooms with yellow pores on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Yellow Spot mushrooms (Nectria peziza)(?) on a wood on Caney Creek Trail (Little Lake Creek Loop Trail) in Sam Houston National Forest, near Huntsville. Texas, March 10, 2018
 Tremella aurantia mushroom parasitizing common wood rotter Stereum hirsutum on a fallen oak on Richards Loop Trail in Sam Houston National Forest. Texas, September 25, 2020
 Common rustgill mushrooms (Gymnopilus penetrans) with side view on rotting pine wood on Richards Loop Trail in Sam Houston National Forest. Texas, December 15, 2020
 Cross section of common rustgill mushrooms (Gymnopilus penetrans) on rotting pine wood on Richards Loop Trail in Sam Houston National Forest. Texas, December 15, 2020
 Yellow flower of rock-rose (Helianthemum carolinianum) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2023
 Yellow flower of rock-rose (Helianthemum carolinianum) on Richards Loop Trail in Sam Houston National Forest. Texas, March 18, 2023
 Yellow trumpet of Carolina jessamine (Gelsemium sempervirens) on Richards Loop Trail in Sam Houston National Forest. Texas, March 3, 2024
 Yellow flowers of Carolina jessamine (Gelsemium sempervirens) on Richards Loop Trail in Sam Houston National Forest. Texas, March 3, 2024
 Blooming wood sorrel (Oxalis) on Angliyskaya Alley in a park of Lomonosov (Oranienbaum). West from Saint Petersburg, Russia, May 23, 2011
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