The Species Orchid Society of Western Australia (Inc)
Diuris (Donkey Orchids)
What are Diuris Orchids?
Diuris are called 'Donkey Orchids' because of their prominent petals, which protrude from the top of the flower like a donkey's ears. The name, Diuris, meaning 'double tailed', describes the narrow, lateral sepals which extend down, under the labelum (lip) for some distance and are often crossed. These two features give Diuris their unique appearance and make them easily distinguished from other species of orchids.
Diuris are confined mostly to the Australian continent with one species endemic to Timor. The Australian species prefer the Southern latitudes and the East Coast, with fewer found growing in the tropics, and those usually in higher rainfall areas.
There are some 40-50 species in Australia, with 20 odd in the South West of Western Australia.
In Western Australia, their flowering period is generally between July and November, which coincides with Mid Winter-Spring, with a few species still flowering into the Summer months of January-February. During the hot, dry Summer, most Diuris, being terrestrials, shrivel all the above ground growth as the below ground tubers become dormant. This is a survival technique common to most Australian terrestrial Orchids.
The most distinctive features of Diuris are the large, broad petals which are often rounded or elongated, and taper sharply to a narrow stalk-like structure at the base, which attaches to the rest of the flower.
The broad dorsal sepal forms a hood over the column and is often reflexed. The lip is three lobed, with the lateral lobes forming wings on each side.
Diuris flowers are primarily yellow, often with blotches of red, purple, pink or brown. They are longer than they are wide due to the tall petals and the length of the lateral sepals. Flower size varies from species to species, but can be from 1 to 6cm measured from top to bottom.
Diuris have grass-like leaves with a central, flower bearing stem that grows, sometimes, up to a metre tall, depending on the species.
Many Diuris are quite common and can be found growing in large clusters or groups due to the vegetative growth of their tubers. They also reproduce from seed, with the seed capsules maturing in a matter of weeks.
It is common to see natural hybrids in the wild, a fact which has caused many problems for taxonomists.
Diuris are a very distinctive and beautiful group of orchids, and are quite easy to cultivate given an understanding of their natural conditions.