This largely midwestern tetraploid (2n = 32) differs from var. coridifolium in its white to pale pink or bluish rays (versus usually bluish), generally shorter and less branched inflorescence, with more ascending branches, and its larger primary leaves, mostly 5-12 cm long and up to 11 mm wide (versus 3-5 cm long and up to 8 mm wide). It occurs mostly on damp lowlands and ponded sites, or occasionally on seasonally damp uplands, often with base-rich soils. Var. strictior is widespread in Ind., Ill. and Mo., where there appears to be introgression with racemosum, and it extends east to Appalalachian regions from New England to N.C. (Sm, F, Y, W). In Ky. var. strictior has been reported from CALL (Fuller 1980) and elsewhere (M), but verification is needed. A coll. from NELS (KY) appears to be this taxon: C.G. Gunn #2054, 18 Sep 1960, prairie patch on Ballard Farm, N of US 31E, on first lane S of Balltown. An unusually robust coll. from BELL (KY) may also be referred here: W. Meijer, 16 Oct 1982, Pine Mt. State Park. Further south, var. strictior is replaced by var. subulifolium (Torr. & Gray) Nesom, which probably extends into the cedar glades of central Tenn., and may also be expected in Ky.