Rudbeckia triloba L.
Family: Asteraceae
brown-eyed Susan,  more...
Rudbeckia triloba image
John Hilty  

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.

Biennial or short-lived perennial 5-15 dm, moderately hirsute or strigose to subglabrous; lvs thin, sharply toothed to subentire, the basal ones broadly ovate or subcordate and long-petiolate, the cauline mostly narrower and shorter-petiolate or sessile, usually some of the larger ones deeply trilobed or seldom even pinnatifid; rays 6-13, yellow or orange, 1-2(-2.5) cm; disk dark purple or brown, hemispheric or ovoid, 8-15 mm wide; receptacular bracts glabrous, abruptly narrowed to a short but distinct awn-tip often shortly surpassing the disk-cors; pappus a minute crown; 2n=38, 57, the triploid more northeastern. Woods and moist soil; Conn. to Mich., Io., and Nebr., s. to Fla. and Tex. June- Oct. Most of our plants belong to the widespread var. triloba, with the lvs often (not always) well over 5 cm, some of them generally trilobed with the lobes generally acute, rarely any of them pinnately lobed. The var. pinnatiloba Torr. & A. Gray occurs on the Gulf coast of w. Fla. and disjunct in the Blue Ridge of N.C. and sw. Va. (where it has been called R. beadlei Small). It is a smaller and more delicate plant, with the lvs to 5(-8) cm, some of them generally pinnately few-lobed, the lobes often obtuse.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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Rudbeckia triloba image
John Hilty  
Rudbeckia triloba image
Rudbeckia triloba image
John Hilty  
Rudbeckia triloba image
Rudbeckia triloba image
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern   
Rudbeckia triloba image
William S. Justice @ USDA-NRCS PLANTS Database  
Rudbeckia triloba image
Zoya Akulova  
Rudbeckia triloba image
Zoya Akulova