Rudbeckia triloba L.

Browneyed susan (en), Rudbéckie (fr)

Species

Angiosperms > Asterales > Asteraceae > Rudbeckia

Characteristics

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.
More
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.
Life form perennial
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) 0.75 - 1.0
Mature height (meter) 1.0 - 1.5
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Light 5-8
Soil humidity 3-6
Soil texture 3-4
Soil acidity 2-8
Soil nutriment -
Hardiness (USDA) 5-8

Usage

Uses -
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by seedlings. Seeds needs stratification.
Mode seedlings
Germination duration (days) 5 - 21
Germination temperacture (C°) 13
Germination luminosity light
Germination treatment stratification
Minimum temperature (C°) -29
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Rudbeckia triloba habit picture by Belle W (cc-by-sa)

Leaf

Rudbeckia triloba leaf picture by Jan Veitch (cc-by-sa)
Rudbeckia triloba leaf picture by Jan Veitch (cc-by-sa)
Rudbeckia triloba leaf picture by Jan Veitch (cc-by-sa)

Flower

Rudbeckia triloba flower picture by Steven Harding (cc-by-sa)
Rudbeckia triloba flower picture by Libby Janes (cc-by-sa)
Rudbeckia triloba flower picture by Hannah Prokop (cc-by-sa)

Distribution

Rudbeckia triloba world distribution map, present in Austria, Canada, United Kingdom of Great Britain and Northern Ireland, Ukraine, and United States of America

Identifiers

LSID urn:lsid:ipni.org:names:241776-1
WFO ID wfo-0000134497
COL ID 4TMCT
BDTFX ID 122370
INPN ID 810919
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Rudbeckia biennis Peramibus hirtus Rudbeckia beadlei Rudbeckia scabra Centrocarpha triloba Rudbeckia aristata Centrocarpha aristata Centrocarpha triloba Rudbeckia triloba var. beadlei Rudbeckia triloba

Lower taxons

Rudbeckia triloba var. rupestris Rudbeckia triloba var. pinnatiloba