Irises

Dutch Iris Stinking Iris Yellow Iris Bearded Iris

What are they?

Irises are typically either herbaceous perennials with spreading root stocks that flower in summer, or arise from bulbs and flower in spring. Most species have sword-like or broadly grass-like leaves and are similar to members of the lily family in many ways.

Where are they found?

Both herbaceous and bulb irises are popular garden plants and may be found as relics or 'escapes' from cultivation in grassy or disturbed places such as roadsides, cemeteries (where they may spread voluntarily from original plantings) and urban environments. Our native species are plants of wet ground, shady places and churchyards.

Identification

The structure of iris flowers readily sets them apart from the flowers of other plant families. The three outer petals (technically called tepals in this group) have narrow bases and broad, flattened distal parts - in horticulture these are called 'falls'. The three inner tepals are smaller and erect (and are often called 'standards'). The species in our area can be identified by studying their flowers and details of the leaf shape. Species with simple or rhizomatous root systems tend to form clumps and have laterally flattened leaves that stand upright like sword blades. Species with a bulbous or tuberous root system more typically have curved and channeled leaves that clasp the stem at the base.



Yellow Iris      Iris pseudacorus

Native. Generally found in wetland habitats, especially around ponds and in swamp woodland, but sometimes also found as a garden relic or throw-out in drier places. Flowers late May to July. Can be told from yellow forms of Bearded Iris by the greener (not blue-green) leaves which are not as stiff as those of Bearded Iris.

Yellow Iris Yellow Iris Yellow Iris Yellow Iris
Habit
Flower
Flower
Early leaves
Yellow Iris Yellow Iris Yellow Iris Yellow Iris
Leaves
Leaf tip
Seed capsules
Old seed capsules


Stinking Iris      Iris foetidissima

Locally native in shady places and woodland, but also widespread as a garden escape and (especially) in churchyards. Flowers May to June. Flowers an unusual colour and difficult to describe, being pale creamy-yellow to brownish-yellow with veins coloured in varying intensities of purple; the overall effect is a rather 'muddy' flower from a distance. This species suffers greatly from a rust fungus which produces heavy spotting on the leaves.

Stinking Iris Stinking Iris Stinking Iris Stinking Iris
Habit
Flowers
Flower
Flower
Stinking Iris Stinking Iris Stinking Iris Stinking Iris
Leaves
Leaf close-up
Leaf with rust spots
Seed capsules


Bearded Iris      Iris germanica

Widely grown as a garden plant and occasionally found as a garden throw-out on roadsides and in waste places. Flowers May to June, sometimes later. Flowers of garden cultivars come in an amazing array of colours from white through pink to deep maroon, purple, blue or yellow, while many are bicoloured.

Bearded Iris Bearded Iris Bearded Iris
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Flower
Flower
Bearded Iris Bearded Iris Bearded Iris Bearded Iris
Flower
Flowers
Flower
Leaves


Siberian Iris      Iris sibirica

Occasionally grown as a garden plant and rarely found as a garden throw-out. Flowers May to June. Smaller and more delicate than Bearded Iris and other garden cultivars. Stems hollow, tubular (basal) part of flower relatively short - 4-7mm long - and the flower bract is papery and brown at the time of flowering.

Siberian Iris Siberian Iris Siberian Iris Siberian Iris
Habit
Flowers
Flower
Lower petal
Siberian Iris Siberian Iris Siberian Iris
Flower bract
Seed capsules
Hollow stem


Hybrid Irises     

Occasionally grown as a garden plant and rarely found as a garden throw-out or where deliberately planted around village ponds. Flowers May to June. An assortment of cultivated varieties are grown in cultivation, mostly involving Iris versicolor, I. ensata and I. laevigata, for use in damp soil or around ponds. Hybrids between these species are also produced and many appear to be of unknown parentage and do not key readily to any of the known species. Such plants typically have rather large flowers with broad petals and share the pith-filled stems and partially green flower bracts that help to distinguish them from Siberian Iris.

Hybrid Irises Hybrid Irises Hybrid Irises
Flower
Leaves
Flower bracts
Hybrid Irises Hybrid Irises
Seed capsule
Pithy stem


Pyrenean Iris      Iris latifolia

(English Iris) Native to the Pyrenees. Occasionally grown as a garden plant and once found naturalised at Hingham, Norfolk. Flowers May to June. Flowers a rich, clear blue. Leaves, which are not flattened like those of most other large iris species, die down in winter.

Pyrenean Iris Pyrenean Iris Pyrenean Iris Pyrenean Iris
Habit
Flower
Flower close-up
Flower close-up


Dutch Iris      Iris x hollandica

Occasionally grown as a garden plant and rarely found as a garden throw-out. Flowers May to June. Large, showy flowers that can be white, yellow or any shade of blue or purple - ir mixes of those colours. More often grown commercially for cut flowers than as a garden plant and doesn't seem to persist long in the wild. Leaves, narrow, arching, folded along their length to give a u-shaped cross-section.

Dutch Iris Dutch Iris Dutch Iris Dutch Iris
Habit
Flower
Flower
Flower
Dutch Iris Dutch Iris Dutch Iris Dutch Iris
Flower
Flower
Leaf base and stem
Leaf


Reticulate Dwarf Iris      Iris reticulata

Commonly grown as a garden plant and popular for planting in cemeteries. Though not officially recorded 'in the wild' in East Anglia, this species is common enough to attract the attention of anyone studying plants in the area. Flowers late February to March. Small plants, to only 30cm or so high, growing from bulbs and often forming discreet clumps.

Reticulate Dwarf Iris Reticulate Dwarf Iris Reticulate Dwarf Iris
Flowers
Flower
Flower close-up