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Information Panels : Aril Irises

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Authors: RNDr. Pavel Sekerka, Ing. Marketa Machackova, Mgr. Milan Blazek

Aril Irises have beard, but they are not classified with the bearded irises because they are so different. What is typical for them is a white fleshy collar (aril) on one end of the seed. There are series Oncocyclus, Regelia, Hexapogon a Pseudoregelia in this group. Mostly first two of them are found in gardens.


Oncocyclus Series
Rhizomatous irises, rhizomes are beadlike flashy at point where leaves come out. Foliage sprouts in autumn mostly and it pulls back in late spring. Stem is single-blossomed. Flowers are large with a distinctive beard and are heavily veined. They grow in desert-like areas from east Mediterranean to central Asia. They are divided into two groups:


1) Thermophilic irises of the Holy Land are quite tall with long leaves of narrow or slightly bent shape. Mostly having dark purple to almost black flowers. They don’t tolerate frost and can be grown only in a greenhouse in local climate.

2) Second group are lower irises with shorter leaves of falcate shape and large flowers. They are difficult to grow, because they can’t stand summer and fall humidity. The best for them are rock-plant-greenhouses; some of them can be grown outside if requirements satisfied.

Regelia Series
Rhizomatous irises, rhizomes end into tuber, abundantly branched. Leaves are sword-like and narrow, stems commonly di-bloomed. Flowers have beards on outer; sometimes also on inner; petals. They come from mountains of central Asia. Sometimes following species are grown:

Iris stolonifera Maxim.
It is slightly smaller. Flowers have distinctive brown-purple veining and yellow beard. It grows in 800 – 2400 m altitude along dry creeks and on rocky slopes of
Tadzhikistan and Pamir-Altai.

Iris hoogiana Dykes
This slender iris reach up to 65cm. It spreads fast with stolons (underground rhizomes) in convenient conditions. Leaves are 1cm wide, upright, slightly ashy with a purple base. Fragrant flowers have lavender blue color and orange beards, blooming in May and June. It comes from Pamir, where it grows on hillsides in elevation of 1800m.



Hybrids of Aril Irises


It is possible to hybridize them in-between and also with bearded irises. General name for these is Arilbred. Hybrids combine characters of both parents in the look and also in growing requirements. Because series Oncocyclus and Regelia are difficult to grow, eventual hybrids are more difficult than bearded irises, but much easier than original aril species. Varieties coming from thermophilic species of Oncocyclus series (Iris atropurpurea, I. aurantiaca, I. nigricans) with origins in Jordan Valley and around Dead Sea have mostly very dark to almost black flowers. Unfortunately they are suitable especially for Mediterranean climate like Israel or California. They freeze to death in Czech.


More significant were varieties from breeding Turkish and Caucasian aril irises. The first were these cultivars:


Iris ´Ib-mac´  (C. G. Van Tubergen, 1910) coming from I. iberica   x  I. macrantha  (2n = 44)

´Lady Lilford´ (Foster, 1916) originated from I. paradoxa x I. pallida (2n = 46)

Ismali´ (Foster, 1909) got by crossing  I. iberica x I. pallida (2n = 46)

Regeliocyclus group is one of the hardiest Arilbreds. They come from breeding irises from Regelia series (Iris hoogiana, I. korolkowii a I. stolonifera) with irises from Oncocyclus series (e.g. Iris iberica). The beginnings of this breeding are dated about 100 years back to Holland and C. G. van Tubergen, who started the first experimental hybridizations. His cultivar ´Theseus´ (1915) is grown until today. His very famous follower at the same company was Antoine Hoog. Their plants are characterized by exotic flower look in colors of white, cream, brown or purple, with significant dark purple or brown veining and with an eye. Inner segments are broad and upright, outer curve back.


Onco Hybrid OH
hybrids within Oncocyclus series
Regelia Hybrid 
hybrids within Regelia series
hybrids between Oncocyclus and Regelia with mostly Oncocyclus characteristics
RC hybrids between Oncocyclus and Regelia with mostly Regelia characteristics
OB also called Eupogocyclus (EC), hybrids between Bearded irises and Oncocyclus
Oncobred hybrid OXb hybrids between Tall Bearded irises and Oncocyclus
Regeliabred RB
hybrids between Bearded irises and Regelia
Oncogeliabred OGB also Oncoregeliabred, hybrids between Bearded irises, Oncocyclus a Regelia
Pogo-regelia    PReg. Irises from group Regeliabred but beardless