Rudbeckia hirta

Linnaeus

Sp. Pl. 2: 907. 1753.

Common names: Black-eyed Susan
Endemic
Treatment appears in FNA Volume 21. Treatment on page 57. Mentioned on page 44, 53.

Annuals, biennials, or perennials, to 100 cm (taprooted or roots fibrous). Stems hispid to hirsute (hairs spreading, 1+ mm). 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. Heads borne singly or (2–5) in loose, corymbiform arrays. Phyllaries to 3 cm (faces hispid to hirsute). Receptacles hemispheric to ovoid; paleae 4–6 mm, apices acute, often attenuate, abaxial tips hirsute to hispid. 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. Discs 12–22 × 10–20 mm. Disc-florets 250–500+; corollas proximally yellowish green, distally brown-purple, 3–4.2 mm; style-branches ca. 1.5 mm, apices subulate. Cypselae 1.5–2.7 mm; pappi 0.

Distribution

V21-122-distribution-map.gif

Alta., B.C., Man., N.B., N.S., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Sask., Ala., Ark., Calif., Colo., Conn., D.C., Del., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Miss., Mo., N.C., N.Dak., N.H., N.J., N.Mex., N.Y., Nebr., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Wyo.

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.

Selected References

None.

Key

1 Annuals, biennials, or perennials; stems branched at bases or proximal to or at or near mid heights, leafy mostly toward bases (leaves smaller distally); peduncles usually at least 1/2 plant heights (Gulf Coastal Plain, Florida to Texas) > 2
1 Biennials or perennials; stems branched mostly beyond mid heights, leafy ± throughout; peduncles to 1/3 plant heights > 3
2 Stems branched mostly at or near mid heights; basal leaves oblanceolate, faces hispid to ± sericeous; Georgia to Texas Rudbeckia hirta var. angustifolia
2 Stems branched at or near bases (plants often scapiform); basal leaves obovate to nearly orbiculate, faces scabrous to hirsute; c, s Florida Rudbeckia hirta var. floridana
3 Leaves: basal blades broadly ovate to broadly elliptic, 2.5–7 cm wide (lengths mostly 2 times widths), margins coarsely toothed; cauline (sometimes sessile) lanceolate, ovate, or pandurate (mostly Appalachian Highlands toIllinois) Rudbeckia hirta var. hirta
3 Leaves: basal blades lanceolate to oblanceolate, 1–2.5(–5) cm wide (lengths 3–5 times widths), margins entire or serrulate; cauline blades spatulate, oblanceolate, or broadly linear Rudbeckia hirta var. pulcherrima
... more about "Rudbeckia hirta"
hirsute +  and hispid +
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
Lowell E. Urbatsch +  and Patricia B. Cox +
Linnaeus +
attenuate +  and cuneate +
compound +  and simple +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
ovate;lanceolate;ovate;lanceolate;elliptic +
0.4cm;4cm +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
sessile +  and petiolate +
Black-eyed Susan +
yellowish green +
0.3 cm3 mm <br />0.003 m <br /> (0.42 cm4.2 mm <br />0.0042 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 +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
10mm;20mm +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, Nfld. and Labr. (Nfld.) +, Ont. +, P.E.I. +, Que. +, Sask. +, Ala. +, Ark. +, Calif. +, Colo. +, Conn. +, D.C. +, Del. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Mass. +, Md. +, Mich. +, Minn. +, Miss. +, Mo. +, N.C. +, N.Dak. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, Nebr. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +, Wash. +, Wis. +  and Wyo. +
hispid +  and hirsute +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
discoid +  and radiate +
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 +
15mm;45mm +
abaxially hispid +  and hirsute +
elliptic +  and oblong or oblanceolate +
5mm;10mm +
sessile +  and petiolate +
not glaucous +
greenish;yellowish +
deltate +  and lance-linear +
serrate +  and entire +
2-carpellate +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
persistent +
0 +  and 2 +
coroniform +
3 +  and 21 +
0 cm0 mm <br />0 m <br /> (3 cm30 mm <br />0.03 m <br />) +
bearing subulate enations +, hairy +  and bristly +
pitted +  and smooth +
hemispheric;ovoid +
connate +  and distinct +
2 +  and 5 +
exalbuminous +
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 hirta +
Rudbeckia sect. Rudbeckia +
species +
cylindric +
entire +  and toothed +
100 cm1,000 mm <br />1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
perennial +, biennial +  and annual +
0 cm0 mm <br />0 m <br /> (100 cm1,000 mm <br />1 m <br />) +
shrub +  and subshrub +