Practical
Plants

Iris douglasiana

a perennial evergreen member of the Iris genus in the family Iridaceae.

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Taxonomy and growth

Family
Iridaceae
Genus
Iris
Life cycle
perennial
Foliage
evergreen
Height
0.3 m
Spread
0.6 m
Fertility
Self fertile, Insects
Flower type
hermaphrodite
Pollinators
Insects

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.

Many plants in this genus are thought to be poisonous if ingested, so caution is advised[12]. The roots are especially likely to be toxic[10]. Plants can cause skin irritations and allergies in some people[10].

Material uses

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

A fibre is obtained from the leaves. Traditionally the N. American Indians would take just the one outside fibre from each side of a leaf. This must have necessitated using a huge number of leaves. It makes a beautifully strong and pliable cord or rope[15][7]. It would take a person almost 6 weeks to make a rope 3.5 metres long[7]. The fibre can also be used for making paper[4] The leaves are harvested in summer after the plant has flowered, they are scraped to remove the outer skin and are then soaked in water for 2 hours prior to cooking. The fibres are cooked for 24 hours with lye and then beaten in a ball mill for 3 hours. They make a light tan paper[4]. Plants can be grown for ground cover when spaced about 60cm apart each way[8].

Product or use
Fibre
Product or use
Paper

Ecology and functions

Ecosystem niche
Soil surface

Ground cover

Environment

Range
South-western N. America - California.
Habitat
Grassy slopes and open places[13] on a wide range of soil types.[2]
Light
full sun
Shade tolerance
light shade
Water
high
Hardiness
Zone 7+
Soil textures
sandy, loamy
Soil pH
acid, neutral, alkaline
Tolerances
high wind, maritime exposure, drought
Wind
Yes
Maritime
Yes
Tolerates Nutritionally Poor Soil
No
Drought
tolerant

Propagation

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

Seed - best sown as soon as it is ripe in a cold frame. Stored seed should be sown as early in the year as possible in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for their first year. Plant out into their permanent positions in late spring or early summer. Division, best done after flowering in late summer[11]. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.

Cultivation

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

We have found this species to be exceedingly easy to grow in sun or shade in our medium loamy soil that is slightly acid. It does well in very wet as well as very dry years. It has withstood considerable neglect, forming a very dense clump that seems capable of standing up to grass and other vigorous plants[K]. The following notes, however, suggest a wide difference of opinions over the best conditions for this plant[K]. Requires a rich well-drained lime-free soil[11][13][14]. Another report says that it succeeds in sun or shade in acid or slightly alkaline soils[2]. Requires a moist soil, growing well by water[1]. This species requires a really well-drained soil, dry rather than damp[9]. It succeeds in dry shade according to another report which also says that it is drought tolerant once established[5]. Easily grown in semi-shade in a woodland soil[11]. Tolerates salt spray[2]. Plants are hardy to about -15°c[3]. A very ornamental plant[1], it hybridizes readily, especially with other Pacific coast Irises[2]. Members of this genus are rarely if ever troubled by browsing deer or rabbits[9]. Resents root disturbance, any moving of the plant is best done in early September[2].

References

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

    ↩1↩2

  2. ? Alpine Garden Society Bulletin. Volume 56. Alpine Garden Society

    ↩1↩2↩3↩4↩5

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

    ↩

  4. Bell. L. A. Plant Fibres for Papermaking. Liliaceae Press 1988-00-00

    ↩1↩2

  5. Chatto. B. The Dry Garden. Dent 1982-00-00 ISBN 0460045512

    ↩

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

  7. Coffey. T. The History and Folklore of North American Wild Flowers. Facts on File. 1993-00-00 ISBN 0-8160-2624-6

    ↩1↩2

  8. Thomas. G. S. Plants for Ground Cover J. M. Dent & Sons 1990-00-00 ISBN 0-460-12609-1

    ↩

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

    ↩1↩2

  10. Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995-00-00 ISBN 0-7513-020-31

    ↩1↩2

  11. Grey. C. H. Hardy Bulbs. Williams & Norgate. 1938-00-00

    ↩1↩2↩3

  12. Frohne. D. and Pf�nder. J. A Colour Atlas of Poisonous Plants. Wolfe 1984-00-00 ISBN 0723408394

    ↩

  13. Munz. A California Flora. University of California Press 1959-00-00

    ↩1↩2

  14. Innes. C. The World of Iridaceae

    ↩

  15. Balls. E. K. Early Uses of Californian Plants. University of California Press 1975-00-00 ISBN 0-520-00072-2

    ↩

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