2. Callirhoe bushii Fernald (Bush’s poppy mallow)

C. involucrata (Torr. & A. Gray) A. Gray var. bushii (Fernald) R.F. Martin

C. papaver (Cav.) A. Gray var. bushii (Fernald) Waterf.

Pl. 451 c–e; Map 2046

Stems 35–50 cm long, ascending, densely pubescent with simple hairs and sometimes also, stellate hairs. Basal leaf petioles 10–23 cm long, pubescent with stellate hairs. Basal leaf blades 4–12 cm long, triangular-cordate to broadly ovate in outline, with 3–7 deep palmate lobes, these sometimes irregularly lobed again, relatively broad, the margins usually sparsely and coarsely toothed, the upper and lower surfaces pubescent with simple and occasionally also a few stellate hairs. Leaves of the aerial stems with the blades 3–12 cm long, broadly triangular to ovate-cordate or obovate in outline, with 3(5) deep palmate lobes, these often pinnately lobed again, the margins entire to sparsely and coarsely toothed, the upper and lower surfaces pubescent with simple and usually also stellate hairs. Stipules persistent, 9–15 mm long, ovate, sometimes auriculate. Inflorescences racemes with 7–17 flowers. Bractlets subtending the calyx 8–14 mm long, linear to narrowly elliptic-lanceolate. Buds ovate to broadly ovate, the sepal tips valvate, forming a beaklike projection 6–10 mm long. Calyces 15–27 mm long, the outer surface densely pubescent with simple hairs and sometimes also with sparse 4-rayed stellate hairs near the tip, the lobes 10–17 mm long, lanceolate to narrowly lanceolate. Petals 17–32 mm long, pale rose to more commonly wine red or purplish red. Fruits 9–13 mm in diameter, with 16–23 mericarps. Mericarps indehiscent, 4.0–5.5 mm long, the dorsal surface glabrous, the sides of the fertile portion with a reticulate pattern of thickenings, separated from the inconspicuous sterile portion by a well-developed collar. 2n=56. May–August.

Scattered in the southwestern quarter of the state north to Carroll County and east to Pulaski County (Iowa to Arkansas, west to adjacent Kansas and Oklahoma). Bottomland forests to dry upland forests, bottomland prairies, upland prairies, and calcareous glades; also roadsides, road cuts, railroads, pastures, and open disturbed areas.

This species is sometimes confused with C. involucrata, but the two species differ in a number of subtle characters. In addition to the habit and bud tip characters in the key to species, they also differ in details of the calyx. In C. involucrata, the calyx lobes are strongly nerved, the nerves raised and often whitened. The pubescence on the outer surface of the lobes consists of long, spreading simple hairs that have somewhat pustular bases and are somewhat fused into irregular fascicles, as well as shorter 4-rayed stellate hairs that are mostly loosely appressed. In C. bushii, the calyx lobes are less strongly veined and generally not raised into whitened ridges. The pubescence of the outer surface is mostly of simple spreading hairs, these not fasciculate, with shorter stellate hairs absent or sometimes sparse and near the tips.

Fernald (1950), Gleason (1952), Steyermark (1963), and some other authors included Missouri in the distribution of the closely related C. papaver. That species occurs only to the south and east of Missouri, and is distinguished from C. bushii by its narrower leaf lobes, narrower (or absent) floral bractlets, and less pubescent stems (Dorr, 1990). The character of appressed vs. spreading pubescence used by Steyermark (1963) to distinguish C. papaver from C. bushii is too variable to differentiate these species.