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Iris unguicularis

Algerian Iris · Winter-flowering Iris

Family IridaceaeGenus Iris

A lilac iris with a white and yellow striped blaze on each hanging petal, among dry grass
FlowerVassilPublic domain

About the plant

What it is and where it grows — not part of any germination protocol.

The plant

Habit
PerennialExtension Gardener Plant Toolbox
Habit
rhizomatous geophytePlants of the World Online
Height
1-1.5 ft30-45 cmExtension Gardener Plant Toolbox
Spread
2 ft60 cmExtension Gardener Plant Toolbox
Flower
Gold/Yellow, Purple/Lavender, WhiteExtension Gardener Plant Toolbox
Blooms
Spring, WinterExtension Gardener Plant Toolbox
Native range
Algeria, East Aegean Is., Greece, Kriti, Lebanon-Syria, Morocco and elsewhereGBIF Backbone Taxonomy
Hardiness zones
7-9Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), SandExtension Gardener Plant Toolbox
Soil pH
Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally DryExtension Gardener Plant Toolbox

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • The Algerian iris flowers in winter and early spring. Its flowers are fragrant, with perianth tubes up to 20 cm long, and its cultivar 'Mary Barnard' has gained the RHS Award of Garden Merit. Wikipedia: Iris unguicularis

Protocol

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 3 months from start to step 2. Germination happens during step 2, in 56 days.

100% germination in 21–56 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Iris p. 156Public domain
Show the original text
Iris (Iridaceae). This genus gave -not only great diversity in germination behavior but also some of the most extended multicycle germination observed. Germination is always hypogeal, and true leaves develop in 'a week or two once the radicle emerges even when germination was delayed for years. Empty seed coats and deformed seeds are relatively easy to recognize so that seed counts and percent germination are accurate. A major problem is how to stimulate the germination of Oncocyclus and Regelia Iris since they have such extended natural germinations. Panayoti Kelaidis of the Denver Botanical Garden has iritorrmed me that Fritz Kummert In Austria, Frank Norris in Tennessee (USA), and David Shahak in Israel are growing Oncocyclus Iris from seed in large numbers. Panayoti said that there are reports that germination was much improved by rinsing the seed in dilute Chlorox (aqueous NaOCI) and rubbing off the seed coats after which the seeds germ. readily at 40. There are also reports that gibberelic acid and other chemicals stimulate germination. Data is needed using scientific procedures. A recent book, "The Iris" by B. Mathew, is devoted to this genus. Mathew divides the genus into six subgenera with further division into sections and series. His arrangement is used only in part. The species are arranged in alphabetical order for convenience with subgenus or section indicated in parentheses using the abbreviations B (bearded), Bx (beardless), E (Evansia), 'N (Nepalensis), .0 (Oncocyclus), P (Pardanthopsis), A (Regelia), At (Aeticulata), and X (Xiphium). I. unguicularis (Bx) germ. 70-40(5/5 in 3-8 w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Iris p. 156. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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