4a. ssp. australis (Chapman) G.B. Ownbey

C. halei (Small) Fernald & B.G. Schub.

Inflorescences (except those with all cleistogamous flowers) usually extending well past the foliage. Corollas with the upper outer petal 11–14 mm long, the spur blunt and not expanded at the tip. Fruits 15–25 mm long, relatively slender. April–June.

Scattered in the Mississippi Lowlands Division (Atlantic and Gulf Coastal Plains, also Texas and Louisiana north to Kansas and Missouri). Sand Prairies and edges of dry upland forests; also ditches, crop fields, railroads, roadsides, and disturbed sandy areas.

Subspecies australis is almost always found growing in sandy habitats. Steyermark (1963) knew it from only a few sites in Scott and Stoddard Counties, but more recent collections have indicated that it is found at most sites with sandy substrate in the Mississippi Lowlands Division.