In shades of violet, mauve to purple, lavender, pale blue, white or pink.

Iris dichotoma grows from a small fibrous rhizome[2][3] that is stout and very short.

[3] It has numerous typical iris-looking leaves[2][5] that are similar in form to a bearded iris,[6] except fan shaped.

[6] They grow from the base of rhizome (i.e. basal) and are sword-shaped,[4][6][8] greyish green and slightly curved.

[2][8] They fully open out in just a couple of minutes,[13] but only last one day,[9][11][16] as they twist into tight little spirals after dark and then drop from the stem.

[10] As the flowers (and nectar) are extremely attractive to hummingbirds and honeybees, cross-pollination can take place and seeds can be formed.

[4][2] The 'claw' (section closest to the centre) is striped,[16] or reticulated (marked with a grid),[2] with yellowish brown and the limb (the end part) has darker spots on a central, pale patch.

[4][2][7] The patch can have a whitish colour tinged with green and the spots can be lilac-mauve,[11] brown-purple,[8] or red-purple.

[11] The plain inner petals are narrowly obovate shaped (teardrop-like), 2.5 cm (1 in) long and 6–8 mm wide, with a retuse apex (rounded end with a depression).

[4] It has very distinct arms on the flower style,[6][2] which are 2.5 cm (1 in) long, with purplish brown markings.

[4] Inside, it has elongated,[6] or elliptic shaped,[4] and dark brown,[4] or brown coloured seeds,[6] that have small wings[4] compared to Iris domestica and related hybrids, which have large round black seeds.

[6] As most irises are diploid, having two sets of chromosomes, this can be used to identify hybrids and classification of groupings.

[4] It has common name of 'Vesper iris' as the blooms open up at around 4:00 pm each day, just in time for Vespers.

[21] The Latin specific epithet dichotoma means divided into two equal portions, equal-branched or split into two,[22][23] or forked.

[14][27][28] Its lack of perianth tube was the feature that originally separated it from other iris species.

[25] It is also found in Mongolia,[6][3][2] Korea,[25][14][4] and in China[6][3][14] within the Chinese provinces of Anhui, Gansu, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shandong, Shanxi and Yunnan.

[25][4] "Iris dichotoma" grows in Quercus (oak) forests, sandy grasslands, and dry sunny areas,[4] which have moist fertile soils.

[4] Iris dichotoma is difficult to cultivate and they are not recommended for amateurs,[2] thought more as a collector's plant.

'Butterfly Magic',[35] 'Candy Lilies', 'Cherry Pie',[36] 'Chic Leopard', 'Chocolate Knight',[37] 'Colorful Stelleroid',[38] 'Dancing Woman', 'Daybreak Sail',[39] 'Dazzler Series', 'Fiery Rhapsody,[40] 'Fire Leaf', 'Happy Yanyan',[41] 'Heart Of Darkness',[42] 'Jungle Colors', 'Kiba Giants' 'Laced Lavender', 'Lost Bar',[43] 'Mandarin Lady', 'Moonlit Hairpin',[44] 'Orange Diamond',[45] 'Pastel Parfait', 'Pink Leopard',[46] 'Romantic Celebration', 'Rosy Brocade', 'Sangria',[47] 'Seiya Hui', 'Sharp Shine', 'Sheng Ni', 'Shining Butterfly',[48] 'Slight Smile', 'Sparkling Fire',[49] 'Star Eyes', 'Spooky World',[50] 'Spotted Dog Hui', 'Starlit Shell',[51] 'Starry Bodhi', 'Summer Candy',[52] 'Summer Snow', 'Sunset Tones'.

[6] In 1967, Samuel Norris, a plant breeder from Kentucky,[54] crossed I. dichotoma with Iris domestica.

[58] They have seedpods between August and October that split to show the black seeds, similar to the blackberry lily (or B. chinensis).

[18] Like many other irises, most parts of the plant are poisonous (especially the rhizome and leaves), and if mistakenly ingested they can cause stomach pains and vomiting.