Rudbeckia sect. Macrocline

Torrey & A. Gray

Fl. N. Amer. 2: 312. 1842.

Synonyms: Rudbeckia subg. Macrocline (Torrey & A. Gray) P. B. Cox & Urbatsch
Treatment appears in FNA Volume 21. Treatment on page 46. Mentioned on page 45.

Perennials, 50–300 cm (robust, rhizomatous or fibrous rooted). Stems green, bluish green, or purplish (usually glaucous). Leaves often bluish green, glaucous; basal (usually persistent to flowering) petiolate or sessile; blades linear, lanceolate to ovate, or oblong to elliptic, usually lobed, bases attenuate, cuneate, or rounded, ultimate margins entire, crenate, dentate, or serrate, apices acute to obtuse, faces glabrous or hairy, sometimes glaucous; cauline petiolate or sessile, blades linear or ovate to pandurate, sometimes lobed, bases auriculate, rounded, or attenuate, ultimate margins entire or dentate to serrate, apices acute to obtuse, faces glabrous or hairy, sometimes glaucous. Heads borne singly or in loose, corymbiform to paniculiform arrays. Phyllaries in 2(–3) series. Receptacles usually conic to columnar (hemispheric to ovoid in R. laciniata); paleae not surpassing cypselae (except in R. laciniata), margins ciliate, apices acute to obtuse or rounded to truncate, attenuate to apiculate, usually hairy. Ray florets 0 or 8–15+; corollas bright yellow. Discs 12–60(–80) × 10–30 mm. Disc florets (100–)150–300(–600+); corollas proximally yellow to yellowish green, distally yellow or greenish to brown-purple; anther appendages sometimes abaxially gland-dotted; styles 3–7 mm, branches 1–2.2 mm, proximal 2/3–4/5 stigmatic, apices acute to rounded. Cypselae (3–)3.5–7.5 mm; pappi usually coroniform or of 2–6, unequal scales, 0.1–2.5 mm, sometimes 0. x = 18.


North America.


Species 13 (13 in the flora).

Selected References



1 Basal and cauline leaves 0.2–1.5 cm wide Rudbeckia mohrii
1 Basal and cauline leaves 2–15(–45) cm wide > 2
2 Blades of basal and proximal cauline leaves elliptic, lanceolate, or ovate, usually 1–2-pinnatifid or -pinnately compound (leaflets/lobes 3–11, distal cauline leaves sometimes lobed as well) > 3
2 Blades of basal, and proximal and mid, cauline leaves elliptic or lanceolate (not lobed, sometimes coarsely toothed, margins of distal cauline leaves crenate, dentate, entire, or toothed, not lobed) > 7
3 Blades of all but distalmost leaves usually 1–2-pinnatifid or pinnately lobed (basal leaves not lobed and proximal cauline usually 3-lobed in var. heterophylla, known only from Florida); receptacles hemispheric or globose to ovoid; disc corolla lobes yellow (rhizomes elongate, slender, plants usually colonial); Rocky Mountains and e United States Rudbeckia laciniata
3 Blades of basal leaves ± pinnatifid to pinnately lobed (distal leaves sometimes not lobed); receptacles columnar, conic, cylindric, or ovoid; disc corolla lobes yellowish green, greenish, or purplish (rhizomes stout, plants usually not colonial); w United States (including Rocky Mountains) > 4
4 Leaves sparsely to densely hairy on abaxial or both faces > 5
4 Leaves usually glabrous, sometimes sparsely hairy on veins abaxially > 6
5 Leaves moderately to densely hairy (both faces); rays 0; pappi of 4 scales, to 1 mm; Washington Rudbeckia alpicola
5 Leaves sparsely hairy (abaxial faces); rays 8–21; pappi coroniform or of scales, 0.5–1.5 mm; California Rudbeckia californica
6 Rays 7–15; phyllaries to 1.5 cm (apices acute to rounded); discs 15–35 mm; California Rudbeckia klamathensis
6 Rays 0; phyllaries to 4 cm (apices attenuate); discs 20–60 mm; Colorado Rockies, Utah Rudbeckia montana
7 Mid (and often proximal) cauline leaves sessile, bases of blades usually auriculate (clasping) to truncate, sometimes rounded, faces (one or both) glabrate or hairy, or glabrous > 8
7 Mid cauline leaves petiolate, bases of blades attenuate to cuneate (not clasping), faces (one or both) glabrous or hairy > 10
8 Leaves bluish green (fresh, heavily glaucous; dried blades white under reflected UV light, at least abaxially); discs 40–80 mm; adjoining areas of Arkansas, Louisiana,Oklahoma, Texas (introduced South Carolina) Rudbeckia maxima
8 Leaves green (fresh; dried blades dark under reflected UV light, at least abaxially); discs 12–25 mm; Alabama, Florida, Louisiana, Texas > 9
9 Cauline leaf bases auriculate, clasping; heads (usually 10+) in paniculiform ar-rays; discs 12–16 mm; paleae 4–6 mm; Alabama, Florida Rudbeckia auriculata
9 Cauline leaf bases auriculate or rounded, not clasping; heads (usually to 15) in ± corymbiform arrays; discs 12–25 mm; paleae 6–8 mm (stems often purplish); w Louisiana, e Texas 13. Rudbeckia scabrifolia Rudbeckia scabrifolia
10 Leaf margins serrate or entire, faces usually sparsely to densely hairy (mostly abaxially), rarely glabrous; rays 0; n Rocky Mountains and Pacific states Rudbeckia occidentalis
10 Leaf margins entire, serrate, serrulate, or toothed, faces glabrous or sparsely hairy; rays 7–16; Pacific states or se United States > 11
11 Leaves bluish green (heavily glaucous); California, s Oregon Rudbeckia glaucescens
11 Leaves green (sometimes lightly glaucous); se United States > 12
12 Basal leaf blades 15–50 × 3–9 cm (lengths ± 5 times widths); discs 20–45 mm; paleae 6–8 mm, apices acute (appressed in young heads); cypselae 5–7.5 mm; w Louisiana, e Texas Rudbeckia texana
12 Basal leaf blades 15–60 × 2–8 cm (lengths ± 7 times widths); discs 10–30 mm; paleae 5–6 mm, apices acute to acuminate (erect to spreading in young heads); cypselae 3–5.5 mm; n Florida, s Georgia Rudbeckia nitida