Rudbeckia |
Rudbeckia sect. Dracopis |
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| cone-flower, rudbeckia |
sweet coneflower |
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| Habit | Annuals, perennials, subshrubs, or shrubs [perennials], mostly 10–80(–200) cm. | Annuals, 25–60(–120) cm (taprooted). | ||||||||
| Stems | erect, branched distally or ± throughout. |
green (glaucous, glabrous). |
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| Leaves | cauline; mostly opposite (distal sometimes alternate); petiolate or sessile; blades mostly lanceolate to oblanceolate overall, usually 1–3-pinnately lobed or -pinnatisect, ultimate margins toothed or entire, faces glabrous or hairy (oil-glands scattered and/or submarginal). |
bluish green, glaucous; basal (seldom persisting to flowering) petiolate or sessile, blades elliptic, lanceolate, oblanceolate, oblong, or ovate, not lobed, bases (cauline) auriculate and clasping, margins crenate, entire or serrate, apices acute or acuminate, faces glabrous; cauline sessile, blades elliptic, lanceolate, oblanceolate, oblong, or ovate, bases auriculate and clasping, margins crenate, entire or serrate, apices acute or acuminate, faces glabrous. |
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| Involucres | narrowly cylindric or fusiform to turbinate or broadly campanulate, 1–12+ mm diam. |
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| Receptacles | convex to conic, smooth or finely pitted, epaleate. |
ovoid to conic; paleae surpassing cypselae (margins ciliate), apices obtuse to acute, often mucronate, faces hairy subapically, glabrous near apices. |
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| Ray florets | 0 or 1–8(–13+) (to 100+ in “double” cultivars), pistillate, fertile (except “double” cultivars); corollas yellow or orange, red-brown (with or without yellow/orange), or white. |
6–10+; corollas yellow, sometimes partly orange or maroon (laminae often with proximal maroon splotch). |
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| Disc florets | 6–120+, bisexual, fertile; corollas greenish yellow to orange, sometimes tipped with red or red-brown, tubes much longer than or about equaling funnelform throats, lobes 5, deltate to lance-linear (equal or 2 sinuses deeper than others). |
to 400+; corollas proximally greenish yellow, distally purplish; styles ca. 5 mm, branches ca. 1.7 mm, proximal 1/2 stigmatic, apices subulate. |
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| Phyllaries | persistent, 3–21+ in 1–2 series (connate to 7/8+ their lengths, usually streaked and/or dotted with oil-glands). |
in 2 series (lengths of outer 2–5+ times inner, inner similar to and sometimes interpreted as paleae). |
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| Calyculi | 0. |
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| Heads | radiate or discoid, borne singly or in ± corymbiform arrays. |
in loose, corymbiform arrays or borne singly. |
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| Cypselae | narrowly obpyramidal or fusiform-terete, sometimes weakly flattened, glabrous or hairy; pappi persistent, of 2–5(–10) dissimilar, distinct or connate scales in ± 1 series: 0–5+ oblong to lanceolate, erose-truncate or laciniate plus 0–2(–5) longer, subulate to aristate. |
1.8–2.5 mm; pappi 0. |
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| Discs | 15–30 × 8–15 mm. |
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| x | = 12. |
= 16. |
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Rudbeckia |
Rudbeckia sect. Dracopis |
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| Distribution |
North America [Introduced in Europe] |
c United States; e United States |
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| Discussion | Species 23 (23 in the flora). 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 1. Rudbeckia sect. Dracopis is sometimes recognized at generic rank as Dracopis. DNA-based phylogenetic analyses support its placement in Rudbeckia, where it was treated by Gray as a section. The single species resembles those in sect. Macrocline; it is often placed there based on DNA evidence; the relationship is not uniformly conclusive. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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| Key |
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| Synonyms | Obeliscaria subg. Dracopis, section Dracopis | |||||||||
| Name authority | Linnaeus: Sp. Pl. 2: 906. (1753): Gen. Pl. ed. 5, 387. (1754) | (Cassini) A. Gray: in A. Gray et al., Syn. Fl. N. Amer. 1(2): 263. (1884) | ||||||||
| Source | FNA vol. 21, p. 44. | FNA vol. 21, p. 45. | ||||||||
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