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Common Name: Yellow Flag

General Information

Iris pseudacorus is a perennial plant that can grow up to 1.50 metres tall.
It is harvested from the wild for local use as a food, medicine and source of materials.

Known Hazards

The leaves, and especially the rhizomes, of this species contain irritating resinous substances called irisin and iridin. If ingested these can cause severe gastric disturbances including abdominal pain, nausea, vomiting and diarrhoea. In larger doses they can also cause spasms, staggering and paralysis[, ].
Plants can cause skin irritations and allergies in some people[].

Botanical References

,

Range

Europe, including Britain, from Norway south and east to N. Africa the Caucasus and W. Asia.

Habitat

Damp marshy areas, swampy woods and in shallow water or wet ground on the edges of rivers and ditches[]. Often found in shady places[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	1.50 m
Pollinators	Bees, hoverFlies
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Prefers a humus rich soil[]. Succeeds in water up to 15cm deep[]. Requires a moist soil, especially in early summer. Prefers a position in semi-shade[]. Plants can be grown in quite coarse grass, which can be cut annually in the autumn[].
A delicately scented essential oil is obtained from the dried roots[].
Members of this genus are rarely if ever troubled by browsing deer or rabbits[].
Some named forms have been selected for their ornamental value[].

Edible Uses

The seed is said to make an excellent coffee substitute as long as it is well roasted[, , , , , ]. Caution is advised, it might be poisonous[].

Medicinal

The fresh root is antitussive, astringent, cathartic, emetic, emmenagogue, odontalgic, purgative and rubefacient[, , , ]. A slice of the root held against an aching tooth is said to bring immediate relief[]. It was at one time widely used as a powerful cathartic but is seldom used nowadays because of its extremely acrid nature[]. It can also cause violent vomiting and diarrhoea[]. When dried the root loses its acridity and then only acts as an astringent[].

Other Uses

A beautiful yellow dye is obtained from the flowers[].
A good black dye is obtained from the root if it is mixed with iron sulphate[, ]. It is brown otherwise[].
The root is a source of tannin[] and has been used in making ink[].
A delicately scented essential oil, obtained from the roots, has been used to adulterate the oil of Acorus calamus[].

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. A period of cold stratification improves germination time and rates. 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 in early spring or early autumn. Early autumn is best[]. 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.