Introduction - Royal Irises Project

    The Royal Irises (Iris section Oncocyclus) comprise ten species in Israel and Jordan, all endemic with limited and distinct populations. The Royal Irises have only one big flower on a stem, with a dark patch on the falls, and big, erect petals called ”flags” or standards. The Royal Irises species divided into dark-coloured and light-coloured standards.
   The project has four goals:
(1) recording and conservation of all populations in Israel, (2) monitoring population dynamics, (3) systematic reviewing and (4) pollination ecology research.
    The main objective is to discover the relationship between the Royal Irises’ special characters: solitary giant flower, no nectar reward, dark colour, and male bees lodging. The Royal Irises are known as the first priority for conservation in Israel. And we hope that our conclusions will influence decisions of the appropriate management and conservation priorities of this rare and endemic species.
    The Royal Iris project sponsored by the DFG and is common to Mainz University in Germany, The Hebrew University in Israel and Bethlehem University in the Palestinian Authority. This project aimed to reinforce the connections between three nations, in addition to the conservation targets.

Conservation and population dynamics

    In Rotem database all known populations of Irises are recorded. We try to locate all Irises populations and to determine their extinction probabilities. Few populations are already extinct: in Tel Aviv area, for example, six of seven known populations were extinct. We record population's characters: flowers percentage, fruit set, and number of clones and individuals along the years. All data accumulate in Rotem and available to Nature Parks Authority. A new nature reserve in Beer-Sheva region (see map) suggested for the protection of Iris atrofusca.


    Although many taxonomists dealt with this section in the last 120 years, no quantitative research was held. Many transition forms between species or populations are known from the field. The project's purpose is to examine the speciation trends in the Royal Irises, and connect eco-geographic conditions with morphologic and genetic variance. The research conducted in 1998 revealed that the morphological traits changed along the eco-geographical North-South gradient: flower size, stem height and leaf characters change along the aridity gradient. The results suggesting that the Royal Irises should merge into four morpho-species: Iris lortetii, Iris Bismarckiana (include I. hermona), Iris haynei (include I. atrofusca, I. atropurpurea and I. petrana) and Iris mariae.

Pollination Ecology

    None of the Royal Irises produce nectar as a reward to the pollinators, despite the huge dimensions of the flowers. As expected, almost no visits of insects were observed during daytime. Preliminary observations revealed that during twilight, hundreds of male bees enter into the flowers’ burrows and stay inside all night. We intend to investigate the reasons for this entering of bee males. The main hypotheses are: (1) the Iris flowers scatter a pheromone like smell which attracts the males, (2) the black patch on the falls mimics female nesting holes (3) the huge petals are used as sun rays receptors, and the reward for the pollinator is thermal energy.

Selected literature

Avishai, M. and D. Zohary. 1980. Genetic affinities among the Oncocyclus Irises. Botanical Gazette 141(1):107-115
Rix, M. 1997. Section Oncocyclus. In: A guide to species Iris (ed. by The Species Group of the British Iris Society) Cambridge University Press.
Sapir, Y. 2001. Pollination ecology of Oncocyclus Irises. Aril Society International Yearbook 2001. pp. 94-96.
Sapir, Y., A. Shmida, O. Fragman and H. P. Comes. 2002. Morphological variation of the Oncocyclus Irises in the southern Levant. Botanical Journal of the Linnean Society. 139:



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Introduction page


Royal Irises in Culture and Art


Species list - maps and flowering time 


Genetics and Morphology Research


Pollination of the Royal Irises


Iris Links and Miscelanous 


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