5. Coreopsis tinctoria Nutt. (plains coreopsis, calliopsis)
C. tinctoria var. similis (F.E. Boynton) H.M.
Parker ex E.B. Sm.
C. cardaminifolia (DC.) Torr. & A. Gray
Pl. 275 e; Map
1164
Plants usually
annual, with taproots. Stems (10–)40–120 cm long, glabrous. Leaves distributed
at (5)6–12 nodes along 2/3 or more of the length of the stems, sessile or
short-petiolate. Leaf blades 1.5–10.0 cm long, oblong to elliptic or obovate in
outline, 1 or 2 times pinnately dissected, the mostly 5–25 ultimate segments 1–4
mm wide, narrowly linear to linear-lanceolate, usually somewhat tapered at the
base and tip, the surfaces glabrous. Inflorescences mostly appearing as
panicles, the heads with the stalk mostly 2–5 cm long. Involucre often
reddish-tinged, the outer series of bracts 1–4 mm long; the inner series of
bracts 4–9 mm long. Chaffy bracts linear, not widened at the base or tip. Ray
florets with the corolla 12–20 mm long, with 3(4) deep, sometimes irregular
(appearing rounded or less commonly somewhat jagged) teeth or lobes around the
tip, yellow with a well-differentiated region of reddish brown to brownish
purple toward the base. Disc florets with the corollas 2.5–3.5 mm long, mostly
4-lobed, reddish purple, sometimes with a yellow tube. Style branches with a
short, bluntly pointed, sterile tip. Pappus absent or of 1 or 2 teeth or awns
to 1.5 mm long. Fruits 1.5–3.0 mm long, the base and tip appearing curled or
arched inward at maturity, the angles usually with narrow to broad, pale wings
having entire to slightly irregular margins, the inner face slightly thickened
at 1 or both ends, dark brown to black, 1 or both surfaces usually with
numerous small, lighter-colored tubercles. 2n=24. June–September.
Scattered,
mostly south of the Missouri River (U.S., Canada, Mexico). Glades and banks of
streams and rivers; also ditches, old fields, railroads, roadsides, and open,
disturbed areas.
The native range
of this species has been obscured by its natural spread along disturbance
corridors such as highways and railroads and also its escape from cultivation
in gardens. Some authors have suggested that its original range included at
least the southern Great Plains and Missouri, Oklahoma, Texas, Arkansas, and
Louisiana (Barkley, 1986; Gleason and Cronquist, 1991).
Steyermark
(1963), in the appendix to his manual, added C. cardaminifolia based on
a collection made by Viktor Mühlenbach in the St. Louis railyards. Smith and
Parker (1971) studied the relationship of this taxon to C. tinctoria,
noting the presence of additional material attributable to C. tinctoria
and intermediate specimens from Missouri, but they concluded that there was no
taxonomic or genetic basis for maintaining two species in the complex. Missouri
plants appear to be relatively uniform in having the basal 1/4–1/2 of the
corolla reddish brown to brownish purple. Elsewhere in the range of the
species, a number of variants occur with ray corollas ranging from entirely
yellow (f. tinctoria) to entirely reddish (f. atropurpurea
(Hook.) Fernald). Native Americans derived a dark red dye from the heads of
this species. It was also used medicinally as a tonic and for treatment of
venereal diseases (Moerman, 1998).