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Common Name: Mountain Iris

General Information

Iris douglasiana is a Evergreen Perennial up to 0.30 metres tall.
It is harvested from the wild for local use as a source of materials.

Known Hazards

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

Botanical References

, ,

Range

South-western N. America - California and Oregon.

Habitat

Open woods, grassy slopes, fields and open places[, ] on a wide range of soil types.[]

Properties

Habit	Evergreen Perennial
Height	0.30 m
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

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[]. The following notes, however, suggest a wide difference of opinions over the best conditions for this plant[]. Requires a rich well-drained lime-free soil[, , ]. Another report says that it succeeds in sun or shade in acid or slightly alkaline soils[]. Requires a moist soil, growing well by water[]. This species requires a really well-drained soil, dry rather than damp[]. It succeeds in dry shade according to another report which also says that it is drought tolerant once established[]. Easily grown in semi-shade in a woodland soil[]. Tolerates salt spray[].
Plants are hardy to about -15°c[].
A very variable and ornamental plant[, ], it hybridizes readily, especially with other Pacific coast Irises[]. Iris douglasiana hybridizes with I. bracteata, I. chrysophylla, I. fernaldii, I. hartwegii, I. innominata, I. macrosiphon, I. munzii, I. purdyi, I. tenax, and I. tenuissima[].
Members of this genus are rarely if ever troubled by browsing deer or rabbits[].
Resents root disturbance, any moving of the plant is best done in early September[].

Edible Uses

None known

Medicinal

None known

Other Uses

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[, ]. It would take a person almost 6 weeks to make a rope 3.5 metres long[]. The fibre can also be used for making paper[] 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[].
Plants can be grown for ground cover when spaced about 60cm apart each way[].

Propagation

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[]. 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.