Reticulate-bulbed bulbous irises. Formerly genus Iridodictyum .
Section Hermodactyloides
Irises are extensively grown as ornamental plants in home and botanical gardens. Presby Memorial Iris Gardens in New Jersey, for example, is a living iris museum with over 10,000 plants, while in Europe the most famous iris garden is arguably the Giardino dell'Iris in Florence (Italy) which every year hosts one of the most famous iris breeders' competitions in the world.
The most commonly found garden iris is the bearded German Iris ( I. germanica ), a hybridogenic species, and its numerous cultivars. Various wild forms and naturally occurring hybrids of the Sweet Iris ( I. pallida ) and the Hungarian Iris ( I. variegata ) form the basis of most all modern hybrid bearded irises. Median forms of bearded iris (intermediate bearded, or IB; miniature tall bearded, or MTB; etc.) are derived from crosses between tall and dwarf varieties.
The bearded irises are easy to cultivate and propagate, and have become very popular in gardens. They grow in any good free garden soil, the smaller and more delicate species needing only the aid of turf ingredients, either peat or loam, to keep it light and open in texture. The earliest to bloom are species like
I. junonia
and
I. reichenbachii
, which flower as early as February and March, followed by the dwarf forms of
I. pumila
which blossom during March, April and May. During the latter month and the following one, most of the larger-growing "tall bearded" irises bloom, such as the German Iris and its variety
florentina
, Sweet Iris, Hungarian Iris, Lemon-yellow Iris (
I. flavescens
),
Iris sambucina
,
I. amoena
, and their natural and horticultural hybrids such as