Family Iridaceae > Subfamily Iridoideae > Tribe Irideae.
Of the five Dietes species Dietes bicolor and Dietes grandiflora are the most often seen.
The flowers of D. grandiflora (Large Wild iris) and D. iridoides (Wild iris) are very similar.
Both have been known as D. vegata and they are commonly confused and mis-named.
Some descriptions of D. iridoides are incorrect in regards to the tepal markings.
Both species are found in Queensland and may become environmental weeds.
D. iridoides are smaller plants growing to around 50 cm high.
They are rapidly growing, evergreen, clumping, rhizomatous plants.
New plantlets can form on the flower stems.
The sword-shaped leaves (wider than D. grandiflora) produce a basal fan.
Inflorescence stems are branched and hold many buds.
Each flower lasts 1 day but bursts of new flowers occur every 2 weeks (Fortnight lily).
Each flower, up to 7 cm across, has a white bract under it.
Flowers have 6 free, white tepals in 2 whorls of 3.
The 3 inner tepals have no markings (D. grandiflora do).
In the centre of the flower are petal-like styles that are white with pale mauve tints.
The ends are split and the stigma lies on the underside at the base of the slit.
The 3 outer tepals, opposite (below) the styles, stigmas, and stamens, act as landing pads for pollinators.
Because of this they are the tepals with the markings or nectar guides.
The basal markings are brown to yellow or orange streaks, blotches or spots.
There is some variation between plants.
The obovoid seed pods hold black seeds in the 3 chambers.
Compared to D. grandiflora, D. iridoides are smaller plants with wider leaves and smaller flowers
that have no markings on the inner tepals.
D. grandiflora flowers last for 3 days and D. iridoides for one.
D. iridoides are much less commonly seen (I have no examples of them).