2. Physostegia intermedia (Nutt.) Engelm. & A. Gray (false dragonhead)

Pl. 439 d; Map 1979

Plants usually with rhizomes. Stems 40–120 cm long, with 9–20 nodes below the inflorescence, often somewhat swollen at the base, the basal portion also often with several closely spaced nodes (these leafless at flowering). Leaves progressively shorter toward the stem tip, the foliage leaves usually distinct from the inflorescence bracts, the inflorescences frequently often appearing elevated from the foliage, but the stalk usually lacking pairs of empty bracts. Blades of main foliage leaves 3–14 cm long, 3–14(–18) mm wide, relatively thin and flexible, narrowly lanceolate to narrowly oblong-elliptic or linear, occasionally narrowly oblanceolate, often shallowly cordate or with small basal auricles that clasp the stem, otherwise angled to a truncate or abruptly rounded base usually slightly wider than the stem node, the margins entire, somewhat wavy, or with irregular, very bluntly pointed teeth. Axes of the inflorescences with uniform, dense, very minute hairs. Bracts 2–5 mm long, mostly shorter than the calyces at flowering, lanceolate to occasionally ovate. Calyces mostly somewhat overlapping along the inflorescence axis, 3–6 mm long at flowering, becoming enlarged to 4–7 mm at fruiting, the outer surface densely pubescent with very minute hairs. Corollas 10–18 mm long (shorter or longer elsewhere), lavender to purplish pink or pinkish purple. Nutlets 2.0–3.0 mm long. 2n=38. June–October.

Uncommon, restricted to the Mississippi Lowlands Division (Kentucky, Illinois, Missouri, Arkansas, Oklahoma, Louisiana, and Texas). Swamps and bottomland forests; also ditches, roadsides, railroads, and moist disturbed areas; sometimes emergent aquatics.

This is a less variable species morphologically than the closely related P. virginiana.