Mr. Austin describes it in his 1957 catalog thus:
"This is the original, the world's first horned iris. Represents greatest break in development of an entirely new and highly decorative iris form that has occurred in the last half century of intensive Iris breeding. Customary beards, instead of reposing quietly on the falls in the normal position, are raised and separated from the falls, projecting as striking plumed horns. Coloring is bold and contrasting, brilliant mulberry standards, and snow white falls, prominently edged to match the standards. Beard is orange yellow, changing to white and mulberry. Sets seed readily and has abundant fertile pollen."
If I remember the story correctly, Mr. Austin was visiting the garden of Sydney Mitchell and looking over the seedlings. He spotted a white and purple plicata that had a small bit of flesh raising off the petal at the tip of the beard. Mr. Mitchell told him such monstrosities appeared once in awhile and were discarded to discourage the effect from persisting. Mr. Austin had different visions and using this variety (later introduced as 'Advance Guard') went on to create hundreds of Space Age irises over a short span of time, of which 'Unicorn' was the first. His catalogs were a delightful treasure hunt of games and special offers hidden thruout their overly packed pages and are treasured by collectors today. He was a huge proponent of hybridizing and encouraged everyone to try their hand at it.
Mr. Austin's life was sadly cut short before he could see the true legacy of his creations. The initial derision and dismissal of what was considered ugly by many finally won converts and eventually reached the peak of iris fame when the purple horned 'Thornbird' (Byers, 1989) won the Dykes Medal in 1997.
What a beautiful addition to iris history we have from this lovely horned plicata in its bright carnival colors. But not only does it have beauty and history going for it, it is a wonderful garden plant as well. Vigorous of growth, very hardy everywhere and a reliable and profuse bloomer too. 'Unicorn' really merits the designation as an iris classic.