Rudbeckia triloba

Linnaeus

Sp. Pl. 2: 907. 1753.

Common names: Brown-eyed Susan
Endemic
Treatment appears in FNA Volume 21. Treatment on page 59. Mentioned on page 53.
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Perennials, to 150 cm (rhizomatous). Stems glabrate to hirsute or strigose (hairs 1–2 mm, basal retrorse, others spreading). Leaves: blades ovate to subcordate or elliptic (not lobed), margins serrate, apices acute to acuminate, faces hirsute to strigose; basal petiolate, 10–30 × 2–8 cm, bases truncate or rounded to cordate; cauline petiolate or sessile, ovate to elliptic, proximal usually 3–5-lobed, 2–20 × 1.5–8 cm (smaller, fewer lobed distally), bases rounded to attenuate, sometimes clasping. Heads (10–30) in paniculiform arrays. Phyllaries to 1.5 cm (faces moderately hirsute). Receptacles conic to subhemispheric; paleae 5–6.5 mm, apices cuspidate (tips awnlike, 1.5+ mm), glabrous. Ray-florets 8–15; laminae (corollas yellow to yellow-orange with basal maroon splotches) linear to oblanceolate, 8–30 × 3–8 mm, abaxially sparsely strigose. Discs 8–15 × 10–20 mm. Disc-florets 150–300+; corollas yellowish green basally, otherwise brown-purple, 3–4 mm; style-branches ca. 1.2 mm, apices obtuse to rounded. Cypselae 1.9–2.8 mm; pappi coroniform, to 0.2 mm.

Distribution

V21-130-distribution-map.gif

Ont., Que., Ala., Ark., Colo., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Mass., Md., Mich., Minn., Miss., Mo., N.C., N.J., N.Y., Nebr., Ohio, Okla., Pa., Tenn., Tex., Utah, Va., Vt., W.Va., Wis.

Discussion

Varieties 3 (3 in the flora).

Selected References

None.

Key

1 Cauline leaves (at least some) 5–7-lobed (Florida, Kentucky, North Carolina, Virginia) Rudbeckia triloba var. pinnatiloba
1 Cauline leaves (at least some) 3-lobed > 2
2 Ray laminae 8–17 mm; discs 10–15 mm diam. (20–100 m; relatively widespread) Rudbeckia triloba var. triloba
2 Ray laminae 18–30 mm; discs 15–20 mm diam. (100–1200 m; Iowa, Kentucky, North Carolina, Tennessee) Rudbeckia triloba var. rupestris
... more about "Rudbeckia triloba"
not tailed +, rounded +  and obtuse +
connate +  and distinct +
obtuse;rounded +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +
indeterminate +  and determinate +
Lowell E. Urbatsch +  and Patricia B. Cox +
Linnaeus +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
2 cm20 mm <br />0.02 m <br /> (8 cm80 mm <br />0.08 m <br />) +
rounded +  and attenuate +
compound +  and simple +
ovate;subcordate or elliptic +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
0.1 cm1 mm <br />0.001 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
barbellulate +  and barbellate +
sessile +  and petiolate +
ovate +  and elliptic +
Brown-eyed Susan +
yellowish green +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
hairy +  and glabrous +
flattened +, fusiform-terete +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
10mm;20mm +
Ont. +, Que. +, Ala. +, Ark. +, Colo. +, Conn. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Mass. +, Md. +, Mich. +, Minn. +, Miss. +, Mo. +, N.C. +, N.J. +, N.Y. +, Nebr. +, Ohio +, Okla. +, Pa. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +  and Wis. +
hirsute +  and strigose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
discoid +  and radiate +
in loose , corymbiform to paniculiform arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.1 cm1 mm <br />0.001 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
fusiform;turbinate or broadly campanulate +
linear +  and oblanceolate +
sessile +  and petiolate +
not glaucous +
greenish;yellowish +
deltate +  and lance-linear +
2-carpellate +
0.5 cm5 mm <br />0.005 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
persistent +
0 +  and 2 +
coroniform +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
3 +  and 21 +
0 cm0 mm <br />0 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (8 cm80 mm <br />0.08 m <br />) +
bearing subulate enations +, hairy +  and bristly +
pitted +  and smooth +
conic;subhemispheric +
connate +  and distinct +
2 +  and 5 +
exalbuminous +
glabrate +  and hirsute or strigose +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Compositae +
Rudbeckia triloba +
Rudbeckia sect. Rudbeckia +
species +
cylindric +
entire +  and toothed +
100 cm1,000 mm <br />1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
0 cm0 mm <br />0 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
80 cm800 mm <br />0.8 m <br /> (200 cm2,000 mm <br />2 m <br />) +
shrub +  and subshrub +