Practical
Plants

Rudbeckia hirta

Black Eyed Susan

a biennial or perennial member of the Rudbeckia genus in the family Compositae.

No photo available

Taxonomy and growth

Life cycle
biennial, perennial
Height
2 m
Spread
0.5 m
Fertility
Bees, Hoverflies
Flower type
hermaphrodite
Pollinators
Bees, Hoverflies

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

This plant is reputed to be poisonous to cattle, sheep and pigs[3].

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

An infusion of the roots has been used in the treatment of colds, dropsy and worms in children[9]. A warm infusion of the root has been used as a wash on sores and snake bites[9]. The ooze from the roots has been used as drops to treat earaches[9].

Material uses

This section contains historical Plants For A Future notes marked noncommercial.

A yellow dye is obtained from the flowers[9].

Environment

Range
N. America. An occasional garden escape in Britain[4].
Habitat
Disturbed soils in Texas[10].
Light
full sun
Shade tolerance
light shade
Water
moderate
Hardiness
Zone 4+
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerances
high wind
Wind
Yes
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Seed - sow April in a greenhouse. Only just cover the seed. Germination should take place within 2 weeks, prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer[K]. The seed can also be sown in situ[2].

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

Succeeds in an ordinary medium soil in sun or shade[2]. Requires a moist soil[1]. Prefers a well-drained soil[6]. Dormant plants are hardy to about -25°c[5]. This species is a biennial or short-lived perennial[7]. Some named forms have been selected for their ornamental value[7]. Members of this genus are rarely if ever troubled by browsing deer[8].

References

  1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

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  2. Sanders. T. W. Popular Hardy Perennials. Collingridge 1926-00-00

    ↩1↩2

  3. Arnberger. L. P. Flowers of the Southwest Mountains. Southwestern Monuments Ass. 1968-00-00

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  4. Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962-00-00

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  5. Phillips. R. & Rix. M. Perennials Volumes 1 and 2. Pan Books 1991-00-00 ISBN 0-330-30936-9

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  6. Brickell. C. The RHS Gardener's Encyclopedia of Plants and Flowers Dorling Kindersley Publishers Ltd. 1990-00-00 ISBN 0-86318-386-7

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  7. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2

  8. Thomas. G. S. Perennial Garden Plants J. M. Dent & Sons, London. 1990-00-00 ISBN 0 460 86048 8

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  9. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9

    ↩1↩2↩3↩4

  10. Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm

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