Mapping here is provisional. This species is a variable perennial that occurs across most of eastern and central North America, except for much of the southeastern Coastal Plain. Several segregates have been described. Typical spicata may be largely northeastern, but distinction from var. leptostachys remains somewhat uncertain. The latter is known mostly from calcareous regions of east-central states (PL), and has been considered typical of drier sites than var. spicata (F, Cr). However, clear ecological differences have not been documented in Ky., Tenn. (Ch), Mo. (Y) or further east (W). Based on D.J. Bogler (in Y) and Ch, cauline leaves in var. spicata are more numerous (ca. 8-18 versus 5-9) but mostly narrower (ca. 0.5-1.5 cm versus 1.5-2.5 cm) and more tapered (versus rounded) at base; the leafless stem portion below the spike is shorter (2-5 cm versus 4-15 cm); the calyx has a longer tube (1-1.5 mm versus 0.5-1 mm) and less developed auricles between lobes (0-0.5 mm long versus 1-1.5 mm). Other potential variants need assessment. A coll. from POWE (DHL) may be referable to the northern var. campanulata McVaugh (with flowers relatively few in raceme; calices campanulate; corollas small and purplish-blue; anthers white; capsules globose), and B reported var. originalis McVaugh (to be determined) from several counties, but these taxa have been included within var. spicata by some recent authors (Y, W). F also reported the southeastern var. scaposa McVaugh from Ky., but colls. have not been located.