Circinaria contorta is a crustose lichen species characterized by its grayish-brown to dark brown thallus, often forming rosettes or patches on calcareous rocks and tree bark. In East and Central Texas, it is commonly found growing on limestone outcrops, cedar elm, and live oak trees, particularly in areas with high humidity and moderate to full sun exposure. The species thrives in the region's temperate climate, typically fruiting in late winter to early spring, producing numerous apothecia with brown to dark brown discs.
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on limestone near the river in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019 Unnamed Road, Johnson City, TX 78636, USA
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on sandstone outcrops in an oak and red cedar forest at Lake Somerville Trailway near Birch Creek Unit of Somerville Lake State Park. Texas, January 25, 2019 Lake Somerville Trailway, Somerville, TX 77879, USA
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on remains of concrete bordering in Old Independence Cemetery near Independence. Texas, February 10, 2019 8675 Coles Rd, Brenham, TX 77833, USA
Close up of chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on remains of concrete bordering in Old Independence Cemetery near Independence. Texas, February 10, 2019 8675 Coles Rd, Brenham, TX 77833, USA
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on concrete remains near the columns in Old Bailor park. Independence, Texas, February 27, 2019
Spreading chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on concrete remains near the columns in Old Bailor park. Independence, Texas, February 27, 2019
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) together with some powdery lichen on concrete remains near the columns in Old Bailor park. Independence, Texas, February 27, 2019
Chiseled sunken disk lichen (Circinaria contorta, Aspicilia contorta) on remains of a concrete foundation at the base of stone pillars in Old Baylor Park. Independence, Texas, March 2, 2020 8355 Old Baylor College Rd, Brenham, TX 77833, USA
AI-generated summary of observations
In East and Central Texas, Circinaria contorta has been observed growing on various substrates, including limestone, sandstone, and concrete. The species was found on limestone near a river in Pedernales Falls State Park, and on sandstone outcrops in an oak and red cedar forest at Lake Somerville Trailway. Additionally, it was observed growing on remains of concrete bordering and foundations in Old Independence Cemetery, Old Bailor park, and Old Baylor Park. The lichen was often found in close proximity to other species, such as powdery lichen. Observations were made over several months, from January 2019 to March 2020, suggesting that the species is widespread and adaptable in the region. The ability of Circinaria contorta to grow on different types of substrates highlights its tolerance for varying environmental conditions.