88. Ratibida Raf. (prairie coneflower)

(Richards, 1968)

Plants perennial herbs, with a taproot or a stout, horizontal rootstock (often a short rhizome) and fibrous roots. Stems erect or ascending, unbranched or few- to several-branched, with several longitudinal lines or ridges, moderately to densely pubescent with short, stiff, strongly to occasionally loosely ascending hairs, sometimes nearly glabrous toward the base, also with scattered, minute, sessile, spherical, yellow glands. Leaves alternate, the lower stem leaves short- to long-petiolate, the petioles progressively shorter up the stem, the upper stem leaves usually sessile or nearly so, the bases usually only slightly expanded, not or only slightly wrapping around the stem. Leaf blades 1 or 2 times deeply divided or compound, those of the uppermost leaves occasionally unlobed, variously shaped, the divisions or leaflets linear to lanceolate, mostly tapered at the base, tapered to a sharply pointed tip, the margins otherwise usually entire and with minute, appressed hairs, the surfaces moderately to densely pubescent with short, stiff, appressed to more or less spreading, sometimes pustular-based hairs (sometimes roughened to the touch), usually also dotted with scattered, minute, sessile to impressed glands, with 1 or 3 main vein(s). Inflorescences of solitary terminal heads, occasionally appearing in loose, open terminal clusters, the heads with long, usually bractless stalks. Heads radiate. Involucre narrowly saucer-shaped, the bracts in 2 somewhat similar overlapping series (the outer series longer than the inner series). Involucral bracts about 5–15, those of the outer series narrowly ovate-lanceolate, those of the inner series narrowly lanceolate to nearly linear, usually reflexed at flowering, green, the margins and outer surface moderately to densely hairy, the inner surface not or only sparsely hairy but often with scattered, minute, sessile, yellow glands, the midnerve usually inconspicuous. Receptacle strongly convex to nearly spherical, ovoid, or cylindrical, elongating as the fruits mature, with chaffy bracts subtending the disc florets, these concave and folded around the florets, oblong to oblong-obovate, the abruptly sharply pointed tips somewhat incurved and slightly concave, moderately to densely white-hairy along the margins and toward the tip, also with a large glandular spot on each face, persistent at fruiting. Ray florets 4–15, sterile (lacking stamens and style at flowering and with an ovary that is shorter and thinner than those of the disc florets, not developing into a fruit), the corolla showy, relatively broad or somewhat narrower (in R. pinnata), moderately to strongly drooping at flowering, the short tube densely hairy, the ligule glandular and hairy, at least on the outer surface, yellow, sometimes with a well-differentiated region of reddish brown to brownish purple toward the base (less commonly yellow only near the tip or the yellow color completely absent), withered but sometimes more or less persistent at fruiting. Disc florets 50 to numerous (more than 200), perfect, the corolla yellow to yellowish green, sometimes purplish-tinged toward the tip, not bulbous-thickened at the base, not persistent at fruiting (but sometimes trapped by the subtending bract), the 5 lobes with the outer surface glandular and sometimes also hairy. Style branches with the sterile tip short or elongate and rounded to sharply pointed. Pappus of the disc florets absent or either a low rim or crown or of 1 or 2 minute teeth, when present persistent at fruiting. Fruits oblong in outline, slightly to moderately oblique at the base, flattened (biconvex), 1 or both of the angles (also the tip) often hairy or minutely fringed, the surface usually glabrous, dark brown to black, with fine, sometimes faint longitudinal lines or grooves, sometimes slightly shiny. Seven species, U.S., Canada, Mexico.

All three of the species found in Missouri are cultivated as garden ornamentals.