T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Iris (Bicolor) Dietes bicolor

Kingdom:   Plantae
(Unranked): Angiosperms
(Unranked): Monocots
Order: Asparagales
Family: Iridaceae
Subfamily: Iridoideae
Tribe: Irideae
Genus: Dietes
Species: D. bicolor
Binomial name: Dietes bicolor
Common names: Bicolor Iris, African iris, Fortnight lily, Peacock Flower, Evergreen Iris, Spanish Iris

The genus Dietes is only found in South Africa and on Lord Howe Island which is between Australia and New Zealand.
Dietes bicolor is a clump-forming rhizomatous perennial plant with long sword-like pale-green leaves 1 to 2cm wide, with a double central vein. The erect sword-shaped leaves grow from multiple fans at the base of the clump. The adult plant is approximately 1m wide and 1m tall. It can form large clumps if left undisturbed for years.
The flower (60 mm in diameter) is made up of three functional units, each consisting of an outer tepal and a style branch. Each of these units must be entered separately by the pollinating insect. Nectar is secreted at the base of each of the outer tepals.
The blooms are white to yellow cream and have three dark spots each surrounded by an orange outline. The flowers only last for one day, but because so many buds are produced the plant is almost always in flower from October until January (spring and summer).
The flower is followed by a capsule that may bend the flower stalk to the ground. Ripe seeds (dark brown in colour) are dispersed when the club-shaped capsule (25mm in diameter) dries and splits. The plant can also spread by means of its modified rhizomes which are located below the soil surface.

This plant can be found planted in many public places in New Plymouth.