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FNA | Family List | FNA Vol. 21 | Asteraceae

261. Rudbeckia Linnaeus, Sp. Pl. 2: 906. 1753; Gen. Pl. ed. 5, 387. 1754.

Coneflower [For Olaus (Olof) Johannes Rudbeck, 1630–1702, and Olaus (Olof) Olai Rudbeck, 1660–1740, father and son, professors at Uppsala University, predecessors of Linnaeus]

Lowell E. Urbatsch, Patricia B. Cox

Annuals, biennials, or perennials, mostly 50–300 cm (mostly fibrous rooted or rhizomatous, sometimes taprooted). Stems 1–15+, erect, branched distally, glabrous or hairy, sometimes glaucous. Leaves basal and cauline; alternate; petiolate or sessile; blades elliptic, lanceolate, linear, oblanceolate, ovate, or spatulate, often pinnately lobed to 1–2-pinnatifid, ultimate margins entire, dentate, serrate, or coarsely toothed, faces glabrous or hairy, sometimes glaucous, sometimes gland-dotted. Heads radiate or discoid, borne singly or in ± corymbiform or paniculiform arrays. Involucres (early flowering) hemispheric to rotate, 15–30+ mm diam. Phyllaries persistent, 5–20 in 1–2(–3) series (narrowly triangular to lanceolate or narrowly elliptic, subequal, herbaceous, distally or throughout). Receptacles subspheric to ovoid, or conic to columnar, paleate (paleae mostly tan proximally, green to maroon distally, obovate, concave, each ± clasping a floret, apices acute to cuspidate or truncate to rounded, abaxial tips glabrous or hairy, sometimes gland-dotted, resin ducts 2–3, maroon, 1 medial and 1 near each margin; receptacles plus paleae and florets = discs, 8–80 × 5–30 mm). Ray florets 0 or 5–25+, neuter; corollas (spreading to drooping or reflexed) usually yellow to yellow-orange or bicolor (laminae often proximally maroon or each with a maroon splotch, distally yellow), sometimes wholly maroon (orangish red to maroon in R. graminifolia. Disc florets 50–800+, bisexual, fertile; corollas yellow, yellowish green, or brown-purple (often bicolor), tubes shorter than cylindric to funnelform throats, lobes 5, triangular. Cypselae (black) ± obpyramidal and 4-angled (often minutely cross rugose), faces glabrous, angles sometimes hairy; pappi 0, ± coroniform, or of 2–8+ unequal scales. x = 16, 18, 19.

Species 23 (23 in the flora): North America; introduced in Europe.

The species of Rudbeckia are distributed among three major clades or lineages. Although relationships among the lineages are not robustly resolved, the lineages are treated here as sections (as they have been traditionally). Rudbeckia hirta and sometimes other species of the genus are used in experimental studies relating to initiation of flowering and hairy root culture. Most species are rich sources of phytochemicals that may offer potential for pharmaceutical or other uses.


Cox, P. B. and L. E. Urbatsch. 1994. A taxonomic revision of Rudbeckia subg. Macrocline (Asteraceae: Heliantheae: Rudbeckiinae). Castanea 59: 300–318. Perdue, R. E. Jr. 1957. Synopsis of Rudbeckia subgenus Rudbeckia. Rhodora 59: 293–299.

1 Annuals (stems glabrous); leaves sessile, blades elliptic, lanceolate, oblanceolate, oblong, or ovate (not lobed, bases auriculate and clasping, faces glabrous, glaucous); phyllaries in 2 series (lengths of outer 2–4+ times inner, inner sometimes interpreted as paleae); paleae surpassing cypselae, margins ciliate, faces usually glabrous; pappi 0   261a Rudbeckia sect. Dracopis, p. 45
+ Annuals, biennials, or perennials (if epappose annuals, stems hairy); leaves petiolate or sessile, blades elliptic, lanceolate, linear, oblanceolate, ovate, or spatulate (often lobed, faces glabrous or hairy, sometimes glaucous; if leaves sessile and not lobed and bases auriculate and clasping, then robust perennials); phyllaries in 2(–3) series; paleae sometimes surpassing cypselae, margins usually ciliate, rarely eciliate, faces glabrous or hairy; pappi usually coroniform or of 2–6+ scales, sometimes 0 (sometimes cypselae each with glandular hairs around apices in R. heliopsidis)   (2)
2 (1) Leaves often bluish green, glaucous; receptacles usually conic to columnar (paleae not surpassing cypselae, except in R. laciniata: paleae surpassing cypselae, receptacles sometimes hemispheric to ovoid, disc corolla lobes yellow); ray florets 0 or 8–15+, corollas bright yellow; disc corollas proximally yellow to yellowish green, distally yellow or greenish to brown-purple; cypselae (3–)3.5–7.5 mm; pappi coroniform, or of 2–6 scales 0.1–2.5 mm   261b Rudbeckia sect. Macrocline, p. 46
+ Leaves green, not glaucous; receptacles usually conic to hemispheric, rarely columnar (paleae surpassing cypselae); ray florets 6–25+, corollas usually yellow-orange proximally, yellow distally, sometimes with basal maroon splotch (orangish red to maroon in R. graminifolia); disc corollas proximally yellow to yellowish green, distally usually brown-purple, lobes sometimes yellowish or greenish; cypselae 1.5–3.5(–4) mm; pappi coroniform, or of 8+ unequal scales 0.1–2 mm, or 0 (sometimes cypselae each with glandular hairs around apices in R. heliopsidis)   261c Rudbeckia sect. Rudbeckia, p. 52

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