3. Ratibida tagetes (E. James) Barnhart (short-ray prairie coneflower, green
prairie coneflower)
Pl. 286 c, d;
Map 1216
Plants with a
taproot. Stems 30–60(–100) cm long, solitary (but then often several-branched
from near the base) or clustered. Leaf blades 0.5–9.0 cm long, mostly
oblong-elliptic to oblong-obovate in outline (those of the undivided leaves
linear to narrowly oblong), 1 or 2 times deeply pinnately divided (those of the
uppermost and/or lowermost leaves sometimes undivided), the divisions (2)3–7,
0.3–4.0 cm long, linear to narrowly oblong or narrowly oblong-lanceolate, with 1
inconspicuous vein. Heads positioned mostly shortly above the leaves, the
stalks to 6.5 cm long. Involucral bracts 10–12, those of the outer series
1.5–6.0 mm long, linear to lanceolate, those of the inner series 1–4 mm long,
lanceolate to narrowly ovate. Receptacle oblong-ovoid to short-columnar or less
commonly nearly spherical, 0.8–1.5 cm long. Ray florets 5–10, the corolla 4–9
mm long, yellow or more commonly with a well-defined zone of reddish brown to
brownish purple toward the base, this occasionally entirely masking the yellow
coloration, the outer surface densely short-hairy, both surfaces usually with
scattered, minute, sessile, spherical, yellow glands. Disc florets 50 to
numerous, the corolla 1.5–2.5 mm long, greenish yellow to yellowish green,
sometimes purplish-tinged toward the tip. Style branches with the sterile tip
slender and sharply pointed. Pappus a minute rim or crown. Fruits 1.9–2.8 mm
long, somewhat obliquely oblong, the angle opposite the chaffy bract often with
a minute, orangish brown fringe, the tip and the apical portion of the winged
angle sometimes also with a minute, orangish tan fringe. 2n=32.
August–October.
Introduced,
known thus far only from the city of St. Louis (Wyoming to Arizona east to
Nebraska and Texas; Mexico; introduced in Missouri). Railroads.