Another species look alike variety which I have gathered by page viewed statistics to date are the most popular Siberian Irises with visitors to this blog.
From Aulden Farm Catalogue
Iris sibirica 'Wealden Mystery' £ 5.00
From the same cross as 'Wealden Butterfly' came this stunning plant. Blue standards and style arms, falls ivory but with exquisite blue veining. Floriferous. Ht 90cm
2006 Cumulative Checklist of Siberian Irises
WEALDEN MYSTERY Wells, Olga Reg. 2005 Sdlg. F0B5 SIB (dip.) (36" 91 cm) EM. S. vivid bright blue-violet,upright; style arms bright blue-violet held at 45°, deeper red-violet either side of rib; F. ivory ground, deep yellow-gold hafts, bright blue-violet signal lines radiate out blending to solid blue-violet at tip; small flower, vertical form. Flight of Butterflies X Cambridge
Photo Credit and big hat tip to Alun and Jill Whitehead of Aulden Farm