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.

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"
Lowell E. Urbatsch +  and Patricia B. Cox +
Linnaeus +
Brown-eyed Susan +
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. +
Compositae +
Rudbeckia triloba +
Rudbeckia sect. Rudbeckia +
species +