Rudbeckia hirta |
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black-eyed coneflower, black-eyed susan |
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Habit | Annuals, biennials, or perennials, to 100 cm (taprooted or roots fibrous). | ||||||||||||
Stems | hispid to hirsute (hairs spreading, 1+ mm). |
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Leaves | blades elliptic, lanceolate, or ovate (not lobed), bases attenuate to cuneate, margins entire or serrate, apices acute, faces hispid to hirsute; basal petiolate, blades 8–30 × 0.5–7 cm; cauline petiolate or sessile, blades (sometimes pandurate) 3–20 × 0.4–4 cm. |
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Receptacles | hemispheric to ovoid; paleae 4–6 mm, apices acute, often attenuate, abaxial tips hirsute to hispid. |
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Ray florets | 8–16; laminae (usually uniformly yellow to yellow-orange or with a basal maroon splotch, sometimes mostly maroon) elliptic to oblong or oblanceolate, 15–45 × 5–10 mm, abaxially hispid to hirsute. |
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Disc florets | 250–500+; corollas proximally yellowish green, distally brown-purple, 3–4.2 mm; style branches ca. 1.5 mm, apices subulate. |
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Phyllaries | to 3 cm (faces hispid to hirsute). |
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Heads | borne singly or (2–5) in loose, corymbiform arrays. |
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Cypselae | 1.5–2.7 mm; pappi 0. |
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Discs | 12–22 × 10–20 mm. |
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Rudbeckia hirta |
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Distribution |
AL; AR; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK
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Discussion | Varieties 4 (4 in the flora). Some strains of Rudbeckia hirta are cultivated and/or used in seed mixes for “re-naturalization” and erosion control. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 57. | ||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Rudbeckiinae > Rudbeckia > sect. Rudbeckia | ||||||||||||
Sibling taxa | |||||||||||||
Subordinate taxa | |||||||||||||
Name authority | Linnaeus: Sp. Pl. 2: 907. (1753) | ||||||||||||
Web links |
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