Information Panels : Bulbous Irises

Bulbous irises are peculiar a group of irises in terms of botany and gardening. First descripttion of genus Juno by Leopold Trattinnick is dated back to the beginning of 19^th century. But the most merit in bulb-iris taxonomy have Soviet botanists, especially G. I. Rodionenko. Today, all three separate genera of bulbous irises (Juno, Xiphium, lridodictyum) are again considered as subgenera of a large genus Iris.

Irises of Subgenus Scorpiris (Juno)

They range from subtle to large (higher than 50cm) plants. Bulbs have noticeable, long and thick roots, pulp is smooth and leaves are quite broad and folded in a V shape. Larger species resemble of corn. These irises grow in Mediterranean, Near East and central Asia. There are 56 species described. Flowers season is spring to beginning of summer.

English irises – their ancestor is Iris latifolia (syn.: I. xiphioides) from mountain meadows of Pyrenees. Foliage appears in spring, flowers are violet, blue or white with yellow basal stigma, never completely yellow. They can reach 1m, that’s why they are very suitable as cut flowers. Spanish irises – come from Iris xiphium. Original species grows in West Mediterranean, Corsica and South Italy. Foliage appears in fall and flowers are in colors of blue, violet, white and yellow. They have a long tradition as garden plant, e.g. Phillip Miller in 1732 talked about 16 varieties. They are mostly cut flower, but in this region they aren’t frost hardy. Dutch irises – are a substitution for Spanish ones since the fifties. They are hybrids of Iris xiphium, I. tingitana a I. latifolia. The breeding has been done mostly by Hoog brothers working for van Tubergen Company. Plants are more tolerant to frost and grown mostly as cut flowers 40 – 60cm tall. When growing outdoors, they flower in June and last quite long, but foliage appears the fall before and it can get some frost damage. Winter cover of conifer branches helps.