Iris dichotoma (also known as Vesper iris) is a species in the genus Iris and is also in the subgenus of Iris. It was once formerly known as Pardanthopsis dichotoma as it was placed in a genus of its own before DNA testing resulted in it returning to the genus Iris. It is native to the forests and grasslands of Siberia, China, Mongolia and Korea. It has long greyish green leaves, long branched stems carrying many flowers in summer or late summer. In shades of violet, mauve to purple, lavender, pale blue, white or pink. They appear in the late afternoon at the time of Vespers (a service of evening prayer).

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