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■ (SPEC) Iris pseudacorus L.

1753, Botanical author Linnaeus

Iris pseudacorus L. (Carolus Linnaeus, 1753, Europe); Section Limniris, Series Laevigatae. SPEC 30-64" (75-160 cm); Yellow;

See below:


Linn. Species Plantarum 38. 1753;
Gerarde 1597;
Addisonia, vol. 12: t. 386 (1927) [M.E. Eaton]
Dickson 1794.
English Botany volume 9, 1869"SPECIES II.— IRIS PSEUD-ACORUS. Linn. Plate JICCCCXCV, Bckli. Ic. Fl. Germ, et Helv. Vol. IX. Tab. CCCXLIV. Xiphion Pseudacorus, Pari. Fl. Ital. Vol. III. p. 295..
Rhizome thick, horizontal, creeping. Stem slightly compressed, about as long as the leaves, sparingly branched or simple. Leaves decaying in winter, broadly linear-ensiform, nearly parallel, straight, glaucous green, dim. Spathes terminal and lateral at the extremity of the main stem, usually terminal only on the branches, herbaceous, with extremely narrow scarious borders. Flowers two or three together. Pedicels of the flower opening first in each spathe as long as or longer than the ovary; those of the other flowers shorter; all rather shorter than the mature capsule. Free portion of the perianth tube cylindrical, much shorter than the ovary. Sepals obovate-spathulate ; the claw rather narrow; the lamma much longer and much broader than the claw, oval or suborbicular, reflexed, not bearded. Petals erect, from one-fourth to one-sixth the length of the Sepals, and one-half to one-third that of the stigmas, oblanceolate or oblong-spathulate, with narrow subparallel claws. Capsule 3-celled, oblong-prismatic, bluntly trigonous, with six faint furrows. Seeds roundish-obdeltoid, mucli compressed, with parallel faces, and with a hard light brown slight!}- shining testa. .
*Var. A", genuina.*Iris Pseud-acorus, Boreau, Fl. du Centr. de la Fr. ed. iii. p. G35. Sepals deep yellow, with an orange spot at the base of the oval lamina. Petals oblong, rather abruptly attenuated into the claw. .
*Var. B", acoriformis.* Plate MCCCCXCV. I. acoriformis, Boreau, Fl. dn Ccntr. do la Fr. ed. iii. p. 035. Sepals deep yellow, with an orange spot at the base of the sub-orbicular lamina. Petals smaller in proportion to the sepals and stigmas than in var. a, and with the lamina gradually attenuated into the claw. See more in Library.
Curtis's Botanical Magazine. 48: tab. 2239. 1821, "There does not seem to be sufficient difference between this plant and our common Iris Pseud-Acorus to constitute a distinct species, yet there is something that pervades the whole aspect not quite agreeing with our native species ; nor does it require so wet a soil. It is said to have been imported from Carolina by the late Mr. Lyons ; yet we do not find it recorded as an American species either by Michaux, Pursh, or Nuttall."
Dykes in The Genus Iris, 1913;Description.Rootstock , a stout rhizome with pink flesh, clothed in the fibrous remams of old leaves. Leaves erect, ensiform, 2 feet or more in length, slightly glaucous, especially near the base, and bearing a conspicuous midrib. Stem , 2-3 feet high, much branched, sometimes with equal lateral branches on either side of the same point on the stem. Spathe valves , very like those of I. versicolor, oblong, green with brown but scarcely scarious edge. The outer valve is sharply keeled, 2½-3½ in. long, the inner of equal length but not keeled. 3-5 flowered. Pedicel, 1-2 in. of varying lengths, often too slender to hold the ripe capsule erect. Ovary , trigonal, with hollow sides and a narrow groove down each angle, ½ in. long. Tube , slightly lighter green than the ovary, from which it is not separated by any constriction, ½ in. long. Falls . The haft is broad and narrows suddenly at the base, near which it usually, if not always, bears two raised ridges or flanges, which fit into hollows in the standards. The central line is slightly raised to form a greenish-yellow, pubescent ridge. The blade is broadly lanceolate or ovate or suborbicular, and usually, but not always, veined with brown-purple or violet on a yellow or creamy ground ; or it may bear brown-purple mottlings between the veins. A distinct patch of a deeper shade of yellow is often conspicuous on the blade. Standards , pale yellow, of varying outline, sometimes a mere point as in I. setosa, but usually spoon shaped, about an inch long, lanceolate-unguiculate, winged at the base. Styles , broad, keeled, sometimes oblong, in other specimens almost triangular. Crests , small, quadrate, either of a pale concolor yellow, or veined with purple. Stigma , a prominent tongue. Filaments , cream, slightly longer than the anthers. Anthers , cream to orange, edged with dark purple or wholly purple-brown. Pollen , cream. Capsule , 1½ --2½ in length, oblong, narrowing gradually to a short beak at the apex. Seeds , flattened, D-shaped or nearly circular, with a smooth, light brown outer skin.Observations.This widely distributed Iris is undoubtedly liable to considerable variatlon in the size, shape and colour of the segments of the flower, but it seems inadvisable to distinguish by name some of the forms while others are passed over. For instance, Boreau I.e. gives as a difference between the varieties Bastardi and acoriformi's that the former is not blotched with a deeper shade of yellow at the base of the blade, while in the latter the deeper coloured blotch is conspicuous. The evidence of seedlings goes to show that the presence and absence of this blotch are a Mendelian pair of characters, of which the presence is dominant over the absence. Evidence for this is derived from the fact that self-fertilized seed of some wild plants obtained from the River Wey near Godalming gave one plant on which no blotch was apparent. Moreover, when this plant was in its turn self-fertilized, all the seedlings were without the blotch. Another peculiarity on which a varietal name has been founded is the amount of brown or violet veining present on the segments, cf. var. acoriformis Boreau I.e. This character is, however, very variable. For instance, this Iris grows extensively along a stream between Hyeres and the sea, and a close examination of successive plants growing in close proximity to each other showed that the style-crests were either pure yellow or veined with purple, while the anthers were either wholly of a deep brown-purple or yellow edged with brown. Moreover, the styles were very variable in shape; in some examples the sides were nearly parallel, while in others the divergence was so great that the surface became triangular.I have it on the authority of Mr G. Yeld, of York, that the pale ochraceous yellow unblotched form, known in gardens as Bastardi, was found by members of his family growing in a field near Llanfairfechan in North Wales, and that a certain proportion of seedlings of the golden yellow type are pale yellow-flowered forms. I have little doubt that in all the various forms of I. pseudacorus we are dealing with various combinations of unit characters, which might be proved to behave in accordance with Mendelian principles.The statement of Spach (I.e.) that, in his variety acoroides, the usual callosities were not present at the base of the haft of the falls is uncorroborated, and may possibly be explained by the fact that he may have been dealing with dried herbarium material, in which case it would most probably have been difficult, if not impossible, to distinguish them. As, moreover, the plant was said to come from America, it is not impossible that Spach mistook for I. pseudacorus a specimen of I. versicolor, which in the dried state might well have flowers of a yellow-brown colour, and on which the callosities are perhaps less prominent than on I. pseudacorus.There is in cultivation in gardens a form of I. pseudacorus with variegated leaves, the yellow edge naturally being that towards the centre of each tuft.Of the cultivation of this Iris little need be said, except perhaps that the plant deserves better treatment in our gardens than is usually accorded to it. Though it grows most luxuriantly in the richest damp bog soil, it is still capable of producing a fine effect in any well enriched garden soil. Even in dry sandy soil, it will grow and flower, but, of course, mulching with old manure and leaf soil are well repaid.No hybrids [in 1913] of this species appear to be known, but there seems no reason why crosses should not be successful with such a species, for instance, as I. versicolor, to which it has many affinities.
Prince 1823; Macoun; Farr 1912; Francis 1920; Wing 1920; Thimler 132; Schreiner 1932; Sim. 1939;


Iris acoriformis Bornm.; Iris acoroides Spach; Iris bastardi Spach; Iris curtopetala Delav.; Limniris pseudacorus Fuss; Iris longifolia Lam. et DC; Iris lutea Lam.; Iris paludosa Pers.; Iris palustris, Moench; Iris pseudacorus acoroides flava, Tornab.; Iris pseudacorus Faux acore; Pseudoacorus; pseudoachorus, pseudo-iris palustris Besslr.; Iris sativ, Miller; Xiphion acoroides Alef.; Xiphium pseudacorum Parlat,; Xyridion acorroideum Klatt; Xyridion pseudacorus Klatt.

Chromosome counts

Chromosome counts: 2n=24, Strassb., 1900; 2n=34, Simonet, 1932; 2n=34, Mori, 1957; 2n=24, 32, 34, Skalinska, 1961; 2n=34, Gad. & Klip., 1963; 2n-34, Sorsa, 1963; 2n=24, 32, 34, Wcislo, 1964; 2n=34, Leane, 1971; 2n=32, Lovka & Sus., 1971; 2n=34, Love & Kjell., 1973; 2n=34, Murin, 1974; 2n=34, Pop. & Cesch. 1975; 2n=34, Dyer, 1976; 2n=34, Murin, 1978; 2n=34, Uhrikova, 1978; 2n=24, Natarajan, 1979; 2n=34, Valdes-ber., 1980; 2n=34, Strid. & Fran., 1981; 2n=34, Arohonka, 1982; 2n=34, Dmit. & Parf. 1985; 2n=34, Mao & Xue, 1986; 2n=34, Sok. & Prob., 1986; 2n=34, Králik, 1986; 2n=32, Jav?rková-Jarolímová, 1992; 2n=34, Jav?rková-Jarolímová & M?sí?ek, 1992; 2n=34, Laublin & Cappadocia, 1992; 2n=32, 34, Colasante & Sauer, 1993; 2n=34, Pérez & Pastor, 1994; 2n=24,34, Druskovic & Lovka, 1995. 2n=34=10m+16sm+8st. including 2 pairs of satellite chromosomes, Park et al. 2006; 2n=34, Muratova et al., 2013.


Iris pseudacorus L.
    • forma nyaradyana Prod
  • var. strictum
  • var. acoroformis (Boreau) Dykes
  • var. bastardii (Spach) Dykes
Iris pseudacorus cultivars: 'Acoriformis', 'Acoroides', 'Alba', 'Amazement', 'Amber Moon', 'Bad Schachen', 'Bastardi', 'Berlin Cream', 'Beuron', 'Blondie', 'Brown Bee', 'Column of Gold', 'Come In Spinner', 'Dark Veined', 'Donau', 'Dragonfly Dance'. 'Ecru', 'English Cream', 'English White', 'Esk', 'Fahle Ilge', 'Fatima', 'Flora-Plena', 'Foxcroft Full Moon', 'Foxcroft Moonbeam', 'Fresh Cream', 'Frost End', 'Garden Green', 'Gigant', 'Gigantea', 'Gold Doubloons', 'Golden Fleece', 'Golden Queen', 'Golden Trinket', 'Gold Pagoda', 'Gordonville Cream', 'Gordonville White', 'II Gengold', 'It's Mine', 'Ivory', 'Kentucky Frost', 'Kentucky Moonbeam', 'King Clovis', 'Krill', 'Kurlen', 'Lime Sorbet', 'Linda West', 'Lionheart', 'Longeacuminata', 'Maackii', 'Mandchurica', 'Mini Cascade', 'Motch Alba', 'Mzchetica', 'Nanus', 'Niswonger', 'No Signal', 'Nyaradyana', 'Pagoda Double', 'Parviflora', 'Polished Mahogany', 'Primrose', 'Primrose Cream','Primrose Monarch', 'Procrastinator', 'Pseudacorus Acoroides', 'Pseudacorus Alba', 'Pseudacorus Aurea Vilmoreana', 'Pseudacorus Bastardi', 'Pseudacorus Dwarf', 'Pseudacorus Foliis Variegata', 'Pseudacorus Gigantea', 'Pseudacorus Golden Queen', 'Pseudacorus Immaculata', 'Pseudacorus Mandshurica', 'Pseudacorus Mercedes', 'Rising Sun'?, 'Roccapina', 'Rose On Primrose', 'Ruby Ribands', 'Ruth Werline Aldridge', 'Silver Coeur', 'Sulphur Queen', 'Sun Cascade', 'Sunprint', 'Sun In Splendour', 'Tangarewa Cream', 'Tiggah', 'Turnipseed', 'Typ Keukenhof', 'Umkirch', 'Variegata', 'Wychwood's Multifloral', 'Zitrone', 'Zvetlik's dwarf'


Iris pseudacorus crosses: Advanced Iris pseudacorus crosses:
  • 'Ben's Legacy' ;'Roy's Lines', 'Roy's Repeater'

Distribution and Cultivation

Distribution: Region: Europe to Caucasus, Mediterranean to Iran, in the following states: Denmark, Finland, FOR Great Britain, Ireland, Norway, Sweden, Austria, Belgium, Czech Republic, Germany, Hungary, Netherlands, Poland, Switzerland, BAL, Corsica, France, Portugal, Sardinia, Spain, Albania, Bulgaria, Greece, Italy, KRI, Romania, Sicily, TUE, Yugoslavia, Belarus, Estonia, Latvia, Lithuania, KRY RUC RUE RUN Russia, RUW Ukraine, Algeria, Morroco, Tunisia, 21 MDR 30 WSB 32 KAZ 33 NCS TCS 34 EAI IRN PAL TUR (38)
*Cultivation:*Iris pseudacorus can grow in shallow water most anywhere and can be invasive when grown in natural drainage systems. For this reason it should be isolated from such situations. It grows readily under normal garden conditions in full sun and well-drained soil.

Further Reading


Library search for Pseudacorus


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-- Main.RPries - 2010-02-11
I Attachment Action Size Date Who Comment
20170603_111507Iris Pseudocorus (2RS).jpgjpg 20170603_111507Iris Pseudocorus (2RS).jpg manage 112 K 05 Oct 2017 - 22:46 HollyJohnson2017-04-01 Iris pseudacorus.Photo taken by Holly Johnson at the Iris Society of Minnesota annual show, June3, 2017.
20170603_111518Iris Pseudocorus (2RS).jpgjpg 20170603_111518Iris Pseudocorus (2RS).jpg manage 193 K 05 Oct 2017 - 22:40 HollyJohnson2017-04-01 Photo taken by Holly Johnson at the Iris Society of Minnesota annual show, June 3, 2017.
Addisonia.jpgjpg Addisonia.jpg manage 864 K 16 Nov 2016 - 18:11 BobPries Plate 385 Addisonia
I.pseud.Double99.jpgjpg I.pseud.Double99.jpg manage 76 K 10 Jul 2021 - 14:37 UnknownUser Photo by Sandor Szasz-Iriszkert-Hungary
IMG_1548-X2_i_pseudacorus.jpgjpg IMG_1548-X2_i_pseudacorus.jpg manage 131 K 17 Feb 2016 - 02:05 BrockHeilman Please contact Brock Heilman for image use.
I_pseudacorus_by_JanLauritzen.jpgjpg I_pseudacorus_by_JanLauritzen.jpg manage 64 K 01 Sep 2011 - 17:03 Main.janlauritzen Taken at Government House, Victoria, BC at AIS 2011 Convention
Ipseudacorus02.jpgjpg Ipseudacorus02.jpg manage 61 K 06 Jun 2014 - 21:14 UnknownUser Photo scanned from the Rosalie Figge slide collection
Ipseudacorus03.jpgjpg Ipseudacorus03.jpg manage 76 K 06 Jun 2014 - 21:16 UnknownUser Photo scanned from the Rosalie Figge slide collection
IrispseudacorusHDatsjukSIGNA01.jpgjpg IrispseudacorusHDatsjukSIGNA01.jpg manage 41 K 11 Oct 2014 - 20:13 UnknownUser Photo by H. Datsjuk-SIGNA
IrispseudacorusminiaturePBlack01.jpgjpg IrispseudacorusminiaturePBlack01.jpg manage 44 K 11 Oct 2014 - 20:20 UnknownUser Photo by Paul Black
IrispseudacorusminiaturePBlack02.jpgjpg IrispseudacorusminiaturePBlack02.jpg manage 65 K 11 Oct 2014 - 20:22 UnknownUser Photo by Paul Black
LindaWest.jpgjpg LindaWest.jpg manage 25 K 12 Feb 2010 - 18:07 Main.shanatse I. pseudacorus 'Linda West'
NS19_2473.jpgjpg NS19_2473.jpg manage 137 K 06 Sep 2019 - 09:37 NickKurzenko Falls Church, Virginia, United States, May 25, 2019
NS19_2507.jpgjpg NS19_2507.jpg manage 113 K 06 Sep 2019 - 09:37 NickKurzenko Falls Church, Virginia, United States, May 25, 2019
Primrose.jpgjpg Primrose.jpg manage 30 K 12 Feb 2010 - 18:08 Main.shanatse I. pseudacorus 'Primrose'
Pseudacorus_Bastardii.jpgjpg Pseudacorus_Bastardii.jpg manage 65 K 13 Oct 2010 - 20:58 EleanorHutchison Photo by El Hutchison, near Winnipeg, Manitoba, Canada, Z3
Pseudacorus_Redoute_235cropped.jpgjpg Pseudacorus_Redoute_235cropped.jpg manage 107 K 05 Dec 2013 - 17:30 BobPries Biodiversity Heritage Library
Psued_var.jpgjpg Psued_var.jpg manage 34 K 12 Feb 2010 - 18:09 Main.shanatse I. pseudacorus variegated
SIGNA_09LV070_pseudacorus_resized.jpgjpg SIGNA_09LV070_pseudacorus_resized.jpg manage 49 K 13 Jan 2011 - 13:24 UnknownUser Pries photo
SunCascade.jpgjpg SunCascade.jpg manage 22 K 12 Feb 2010 - 18:10 Main.shanatse I. pseudacorus 'Sun Cascade'
doublepseudo9.JPGJPG doublepseudo9.JPG manage 146 K 24 Jun 2023 - 15:08 UnknownUser Photo by Verna Laurin-Willowdale-ON-Canada
goldenqueen01.jpgjpg goldenqueen01.jpg manage 39 K 08 Mar 2017 - 03:07 UnknownUser Photo by Geles Iris Garden-Lithuania
goldenqueen02.jpgjpg goldenqueen02.jpg manage 53 K 08 Mar 2017 - 03:09 UnknownUser Photo by Geles Iris Garden-Lithuania
ipsbastardii01.jpgjpg ipsbastardii01.jpg manage 16 K 11 Sep 2014 - 16:27 UnknownUser Photo by Seagate Irises-United Kingdom
ipseudacorus01.jpgjpg ipseudacorus01.jpg manage 55 K 23 Aug 2014 - 13:11 UnknownUser Photo by Iris City Gardens
ipseudacorusfloreplena01.jpgjpg ipseudacorusfloreplena01.jpg manage 55 K 23 Aug 2014 - 13:13 UnknownUser Photo by Iris City Gardens
ipseudocorausgoldenqueen01.jpgjpg ipseudocorausgoldenqueen01.jpg manage 30 K 09 Oct 2014 - 20:27 UnknownUser Photo by Rowden Gardens-England
ipseudocorus01.jpgjpg ipseudocorus01.jpg manage 41 K 09 Oct 2014 - 20:17 UnknownUser Photo by Rowden Gardens-England
ipseudocorusfloreplena01.jpgjpg ipseudocorusfloreplena01.jpg manage 22 K 09 Oct 2014 - 20:22 UnknownUser Photo by Rowden Gardens-England
ipsfloraplena01.jpgjpg ipsfloraplena01.jpg manage 20 K 11 Sep 2014 - 16:29 UnknownUser Photo by Seagate Irises-United Kingdom
pseudacorus11.jpgjpg pseudacorus11.jpg manage 36 K 10 Oct 2013 - 20:14 UnknownUser Photo by Alla Chernoguz-Ukraine
pseudacorus4.JPGJPG pseudacorus4.JPG manage 48 K 10 Feb 2012 - 18:05 Main.htb ©2003 Laurie Frazer
pseudacorus5.jpgjpg pseudacorus5.jpg manage 60 K 26 Sep 2019 - 18:49 UnknownUser Photo by Binny Plants-United Kingdom
pseudacoruss_3.jpgjpg pseudacoruss_3.jpg manage 111 K 04 Dec 2013 - 19:44 BobPries Pries photo at Nauvoo Illinois
pseudo03.jpgjpg pseudo03.jpg manage 48 K 17 Jul 2015 - 03:28 UnknownUser Photo by Barry Blyth-Australia
pseudo04.JPGJPG pseudo04.JPG manage 71 K 18 Jun 2014 - 21:20 UnknownUser Photo by Don McQueen,London, Ont. Canada Zone5.
pseudo05.JPGJPG pseudo05.JPG manage 80 K 30 Jun 2014 - 16:15 UnknownUser Photo scanned from the Bee Warburton slide collection
pseudocaurus01.jpegjpeg pseudocaurus01.jpeg manage 65 K 16 Nov 2015 - 21:29 UnknownUser Photo by Svetlana Yakovchuk-Ukraine
pseudocoraus09.jpgjpg pseudocoraus09.jpg manage 70 K 21 Dec 2018 - 19:51 UnknownUser Photo by Kelways-United Kingdom.
pseudocoraus14.jpgjpg pseudocoraus14.jpg manage 50 K 10 Jan 2014 - 15:31 UnknownUser Photo by Darius Gusas-Lithuania
pseudocorus1.JPGJPG pseudocorus1.JPG manage 996 K 06 Feb 2017 - 16:32 UnknownUser Photo scanned from the Glenn Corlew slide collection
pseudocorus2.JPGJPG pseudocorus2.JPG manage 833 K 06 Feb 2017 - 16:34 UnknownUser Photo scanned from the Glenn Corlew slide collection
pseudocorus3.JPGJPG pseudocorus3.JPG manage 998 K 06 Feb 2017 - 16:36 UnknownUser Photo scanned from the Glenn Corlew slide collection
pseudocorus6.JPGJPG pseudocorus6.JPG manage 1 MB 06 Feb 2017 - 16:40 UnknownUser Photo scanned from the Glenn Corlew slide collection
pseudocorus7.JPGJPG pseudocorus7.JPG manage 705 K 20 Apr 2018 - 21:55 UnknownUser Photo by Don McQueen-London,Ont.-Canada Zone 5
Topic revision: r70 - 24 Jun 2023, Harloiris
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