This decaploid (2n = ca. 90) is endemic of central Appalachian regions (FNA 20) . It was recently described by Wieboldt & Semple (2003), but had been known informally as "macroarguta" by M and Campbell et al. (1993). It mostly occurs in relatively mesic sites at the base of forested slopes; arguta occurs more widely distributed in mesic to subxeric woods. Colls. from JACK, OWSL and MCRE (KY) are vegetative, and they may just be abnormal arguta, but Wieboldt did include the one from MCRE. S. faucibus has distinctly larger involucres than arguta (4.5-7 mm long versus 2.5-5 mm), with 3 veins usually evident on phyllaries (versus only the mid-vein enlarged). It also tends to have shorter inflorescence branches, with less secund character and without naked bases. Its basal leaves tend to be abruptly truncate (versus broadly cuneate), and its spreading caudices form extensive clonal patches, often 1-10 sq. m or more (versus < 1 sq. m).