Rudbeckia grandiflora (Sweet) C. C. Gmel. ex DC.
Source: Collecitons database
Family: Asteraceae
Rough Coneflower
Rudbeckia grandiflora image
Perennials, to 120 cm (roots fibrous, caudices often woody). Stems proximally glabrous or sparsely hairy (hairs spreading), distally strigose (hairs ascending). Leaves: blades elliptic, lanceolate, or ovate (± conduplicate, not lobed), bases cuneate to rounded, margins entire or remotely serrate, apices acute, faces strigose, abaxially gland-dotted; basal petiolate, 10-35 × 2-11 cm; cauline petiolate (proximal) to nearly sessile (distal), 4-30 × 1.5-9 cm. Heads mostly borne singly. Phyllaries to 15 mm (strigose and gland-dotted). Receptacles hemispheric to ovoid; paleae 5-6.5 mm, (apical margins glabrous) acuminate-cuspidate, awn-tipped, abaxial tips sparsely strigose. Ray florets 12-25; laminae elliptic to obovate (reflexed), 20-50 × 5-10 mm, abaxially hairy and gland-dotted. Discs 10-30 × 15-25 mm. Disc florets 200-800+; corollas greenish yellow basally and in lobes, otherwise maroon, 3.5-5 mm; style branches ca. 1.8 mm, apices obtuse. Cypselae 2-3 mm; pappi coroniform, to 0.5 mm.
An Ozarkian sp. with larger heads (rays 3-5 cm) and with the lvs hirsute on both sides, barely enters our range in c. Mo. as an introduction.

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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