|Hort. Kew. 1: 70. 1789;|
|Redoute, Les Liliaceae|
| Addisonia 9: 4, 63. Dec. 1924.
Our so-called dwarf-irises represent a group quite different from the larger blue-flags. The groups differ from each other not only in the structure of the flowers and the fruits, but also in the habitats. The natural habitat of the blue-flags is wet; that of the dwarf-irises is dry. Consequently there is a difference in the anchorage and stem-systems. The larger blue-flags have cord-like fleshy roots and stout fleshy rootstocks, while the dwarf-irises have fibrous roots and coarse-wiry rootstocks.
This dwarf-iris flourishes in the plantations of the New York Botanical Garden, as well as in other places farther northward than its natural range. This fact leads one to suspect that the plant never regained all the ground it may have lost during the ice age. Within its range it is most abundant along the main drainers of the highlands. Along these highways, as it were, in post-pleistocene times, it reached the Atlantic seaboard on the east and the Trans-Mississippi country on the west. As there are no great erosion highways running northward from the old Appalachian plant reservoirs, the plant's progress in that direction was, evidently, checked or blocked.
The crested dwarf-iris, however, is one of the few flags that has left a tangible trail behind it in its escape from the old Appalachian Highlands. It spread radially from the high altitudes into the Piedmont and Coastal Plain, and it still maintains a foothold from the higher mountains to near sea-level.
Iris cristata is of wide geographic distribution, in the southeastern United States south of Pennsylvania and Missouri, and consequently of varying habitats. Cliffs, bluffs, rocky hillsides, ravines, and woods are among its native haunts. Plants with albino flowers have been found.
The origin of the type specimens of the crested dwarf-iris is not known. Alton, who first describes it botanically, records that it was introduced from North America into England by Peter Collinson in 1756. It was probably secured in the southern Atlantic States by Collinson's chief explorer, John Bartram, or by one of the half-dozen plant collectors who were then active in that region.
The method of seed-dispersal in the dwarf-irises is quite different from that of the large blue-flags. The corky-coated seeds of the blue-flags merely float away or about on the water of the plant's habitat. Each seed of the dwarf -irises, inhabitants of dry places, has a viscid appendage – aril – by which it may adhere to the feathers of birds or fur of animals, and thus be disseminated.
The crested dwarf-iris has coarse-wiry branching rootstocks with tuberlike thickenings. The branches are dimorphous; the foliage ones very short, with three to six leaves which are closely imbricate at the base and with sabre-like blades one to twelve inches long, the inner much the longer; the flower-branches are mostly one to three inches long, with the small dirk-like leaves more or less enfolded, but not imbricate at the base. The flowers are solitary or two together, faintly scented, exceeding the involucre formed by the upper leaves of the flower-stalk. The pedicel is about as long as the ovary in anthesis, or longer. The hypanthium, surrounding the ovary, is sharply three-angled and with a slight ridge on each face. The perianth-tube is mostly one and three quarters to two and three quarters inches long, very slender, broadly funnelform at the top.
The three sepals are cuneate-spatulate to narrowly obovate, one and a quarter to one and a half inches long; the blade mainly lavender, dark or pale, with a white blotch bordered with violet; the claw is shorter than the blade, with a crest of three beaded ridges, the median one yellow and running to the base of the claw, the lateral ridges yellow with white edges, all extending up into the blotch in the blade. The three petals are spatulate, somewhat shorter than the sepals, lavender, except the deeply channeled purple claw. The three stamens are one half to three quarters of an inch long, w4th the subulate filament tinted with lavender and the yellow anther longer than the filament. The style is filiform, about as long as the perianth-tube. The three style-branches are narrowly cuneate above the slender claw, about one inch long, lavender, more deeply shaded along the midrib. The style-appendages are semi-ovate, about a quarter of an inch long, blunt, undulate. The stigma is semicircular, not lobed, minutely erose. The capsules are ellipsoid or oval, varying to ovoid or obovoid, one half to three quarters of an inch long, often minutely beaked with the persistent style-base, three-lobed, the lobes with a slight median groove, each sinus with a minute groove. The mature pedicels are about as long as the capsules or longer. The seeds are nearly or quite one sixth of an inch long, oval or obovoid, but slightly inequilateral, brown, with the aril-tip curled over the top of the seed-body.
John K. Small
| Dykes, The Genus Iris 1914
Rootstock , a slender rhizome, spreading by means of long stolons ; in cultivation a single rhizome sends out as many as 6 or 8 of these stolons to form new rhizomes for the following year. In the wild state, growth often extends for 8-1 2 in. without any lateral shoots.
Leaves , about 6 in. by ½-½ in. at flowering time, subsequently increasing to as much as I 2 in. by 1¼ in.; ensiform, not very rigid, finely ribbed, of a somewhat yellowish green.
Stem , short, not more than I in., bearing near the base 2-3 reduced leaves.
Spathes , 1-2 flowered, green, sharply keeled, acuminate, slightly inflated, 2½-3 m.
Pedicel , ¼ in.
Ovary , trigonal, with a slight groove on each face, ¼ in. long, tapering at either end.
Tube , 1½-4 in. long, distinctly trigonal, becoming wider above.
Falls . The somewhat blunt and broad obovate blade is not separated by any constriction from the wedge-shaped haft, which bears three parallel ridges. The central ridge is crinkly, white, tipped with orange ; those on either side are orange or brownish yellow on the inner face, beyond which the colour becomes lilac purple. On the blade the end of the central ridge or crest becomes white, tipped and dotted with lilac purple. Around this there is a white patch, edged with deep lilac purple, which shades away into the plain paler lilac of the rest of the blade.
Standards , obovate unguiculate, emarginate, lilac purple.
Styles , narrow, keeled, pale lilac.
Crests8 , long, narrowly triangular.
*Stigma , oblong, entire.
Filaments , white, tinged with pale mauve, attached to the base of the central ridge of the falls.
Capsule , small, not much more than ½ in. long, the outline being a pointed oval, the section trigonal with three sharp angles ; it dehisces completely while still somewhat green and while still hidden in the persistent spathe-valves.
Seeds , small, brown, smooth, oval or globular, with curious, transparent, almost gelatinous appendages, often longer than the circumference of the seeds and twined round them. These appendages quickly shrivel on exposure to the atmosphere.Observations.
This very distinct Iris has been known since the middle of the eighteenth century. There exists at the British Museum a specimen from Bartram's Herbarium, dated 1764 and described as "a sweetscented plant, growing 5 in. high, which spreads much and differs from the Carolina dwarf Iris."The "Carolina dwarf Iris" is probably a reference to I. verna, with which I. cristata was at first confused, e.g. among Pallas' specimens (BM) which are labelled either verna or even pumila.
This confusion is hardly a matter for surprise in view of the fact that in Kentucky, at any rate, cristata and verna are sometimes found in company, though verna is usually found at a greater elevation than cristata (cf. note on Short's specimen (K)).
The points of agreement between I. cristata and I. lacustris are so many and they are both separated by so many characters from all other Irises, that it seems impossible to give both specific rank. It is true that I. lacustris is usually smaller than I. cristata but this character tends to disappear when seedlings are raised, though even in seedlings the closer growth of the more slender rhizomes is still apparent. However, there is no difference except size in the growth of the two plants and size alone is often a matter of soil and climate. Moreover, as the smaller plant comes from the colder, northern region, we are surely justified in looking upon I. lacustris as a mere local form of I. cristata.
As garden plants, both do well in moist soil composed of humus and gravel, in the kind of soil, in fact, in which they grow in their native home on the banks of streams. Both are quite hardy and I. lacustris has, or, at any rate, some plants of it have, a curious habit of flowering at odd times from May until October.
Propagation is easy and is best carried out by cutting away the side-growths soon after the flowering season. The points of the new roots will then be apparent and each of these stolon-like growths is capable of becoming a flowering plant by the next year. Each rhizome that has flowered withers and dies and may therefore be at once discarded, for no fresh lateral growths will make their appearance from it. The plants benefit greatly by this annual remaking of the plantations, and the opportunity should be taken of adding fresh supplies of well-decayed leaf-soil.
I. cristata does not produce seed very readily in cultivation in this country. Even when a few capsules are obtained as the result of artificial pollination, the seeds in each are not numerous. Moreover, germination appears to be difficult, for though I have regularly sown seeds of I. cristata for several seasons past, none have ever germinated except a few from one pod of the variety lacustris. An albino form of this Iris has recently appeared in commerce. It is uncertain whether I. cristata alba was found wild or whether it is of garden origin, although there is reason to believe that it has been found among collected plants.
| Distribution: The distribution of the species gives clues as to its cultural requirements, although plants in cultivation can often tolerate a wider range of variables:
The species is found in the following region: Central & Eastern U.S.A. within the following states and provinces: Illinois, Iowa, Missouri, Oklahoma, Indiana, Ohio, Pennsylvania, West Virginia, Alabama, Arkansas, Georgia, Kentucky, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and Washington DC
Bonap's North American Plant Atlas shows the following map reproduced by permission of Kartesz, J.T., The Biota of North America Program (BONAP). 2015. Taxonomic Data Center. (http://www.bonap.net/tdc). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]
Cristata is usually found in woodlands and is an excellent plant for shade gardens. It has been grown in almost full sun as long as adequate moisture is provided and under those conditions it will grow more rapidly and be more floriferous
|jpg||Dykes_plate_XLVIII_cristata.jpg||manage||57 K||04 Jan 2011 - 15:42||UnknownUser||From Dykes plate|
|jpg||EO-I-CRISTATA_CLUMP.jpg||manage||38 K||17 Sep 2010 - 19:46||UnknownUser||Lorena Reid photo|
|jpg||EP-I-CRISTATA_ALBA.jpg||manage||44 K||18 Sep 2010 - 11:23||UnknownUser||Lorena Reid photo|
|jpg||EQ-I-CRISTATA_BRIGHT_BLUE_CLOSE-UP.jpg||manage||25 K||18 Sep 2010 - 11:26||UnknownUser||Lorena Reid photo|
|jpg||ER-I-CRISTATA_LATE_DARK_BLUE.jpg||manage||37 K||18 Sep 2010 - 11:28||UnknownUser||Lorena Reid photo|
|jpg||Iris Cristata Dwarf Crested Iris in Rock Garden (RS).jpg||manage||662 K||05 Oct 2017 - 18:41||HollyJohnson2017-04-01||A drift of I. cristata at the Minnesota Landscape Arboretum, zone 4b, on May 10, 2017. Photo taken by Holly Johnson.|
|jpg||Iris Cristata in Perennial Garden (2RS).jpg||manage||392 K||05 Oct 2017 - 18:44||HollyJohnson2017-04-01||A clump of Iris cristata. Photo taken by Holly Johnson at the Minnesota Landscape Arboretum, zone 4b, 5/10/2017.|
|jpg||Iris_cristata_Powder_Blue_Giant.jpg||manage||63 K||13 Feb 2015 - 03:58||Main.KWalker||Photo by Ken Walker; Powder Blue Giant|
|JPG||Iris_cristata_Sams_mini_KWW_1.JPG||manage||53 K||13 Feb 2015 - 14:35||Main.KWalker||Photo by Ken Walker; Sam's Mini|
|jpg||Iriscristata02.jpg||manage||80 K||18 Sep 2014 - 03:12||Main.TLaurin||Photo by Adele and Lewis Lawyer|
|jpg||Iriscristata03.jpg||manage||81 K||18 Sep 2014 - 03:14||Main.TLaurin||Photo by Adele and Lewis Lawyer|
|jpg||Iriscristata04.jpg||manage||66 K||18 Sep 2014 - 03:16||Main.TLaurin||Photo by Adele and Lewis Lawyer|
|jpg||Iriscristata05.jpg||manage||58 K||18 Sep 2014 - 03:18||Main.TLaurin||Photo by Adele and Lewis Lawyer|
|jpg||Iriscristatakp9.jpg||manage||58 K||05 Aug 2010 - 16:22||KentPfeiffer||Taken in my garden, zone 5b, on May 8, 2009|
|jpg||PdBlGiant.jpg||manage||58 K||16 Jan 2010 - 19:39||Main.shanatse||I. cristata 'Powder Blue Giant'|
|jpg||SIGNA_09CR020_cristata.jpg||manage||50 K||20 Jan 2012 - 14:51||UnknownUser||Pries photo|
|jpg||SIGNA_09CR020_cristata_enlarged.jpg||manage||21 K||20 Jan 2012 - 14:53||UnknownUser||Pries photo|
|JPG||convention_spring_2014_001.JPG||manage||1 MB||26 Jul 2016 - 17:51||BobPries||Pries photo|
|jpg||cristata.jpg||manage||35 K||16 Jan 2010 - 19:37||Main.shanatse||I. cristata|
|JPG||cristata01.JPG||manage||98 K||22 Oct 2014 - 23:46||Main.TLaurin||Photo by Joe Pye Weed's Garden|
|jpg||cristata02.jpg||manage||64 K||20 Jun 2015 - 03:08||Main.TLaurin||Photo by Barry Blyth-Australia|
|jpg||cristata03.jpg||manage||102 K||17 Jul 2015 - 02:21||Main.TLaurin||Photo by Barry Blyth-Australia|
|jpg||cristata04.jpg||manage||130 K||17 Jul 2015 - 02:23||Main.TLaurin||Photo by Barry Blyth-Australia|
|jpg||cristata1.jpg||manage||263 K||14 Jun 2016 - 23:37||Main.TLaurin||Photo by Marty Shafer/Jan Sacks-Joe Pye Weed's Garden|
|jpg||cristata2.jpg||manage||120 K||05 Jun 2018 - 01:15||Main.TLaurin||Photo by Holly Johnson at the Minnesota Landscape Aboretum-Zone4B|
|jpg||cristata3.jpg||manage||105 K||05 Jun 2018 - 01:17||Main.TLaurin||Photo by Holly Johnson at the Minnesota Landscape Aboretum-Zone4B|
|jpg||cristata33.jpg||manage||99 K||05 Jul 2020 - 01:46||Main.TLaurin||Photo by Holly Johnson|
|jpg||cristata34.jpg||manage||166 K||02 Nov 2020 - 16:33||Main.TLaurin||Photo by Holly Johnson|
|jpg||cristata4.jpg||manage||30 K||16 Jan 2010 - 19:38||Main.shanatse||I. cristata|
|JPG||cristata5.JPG||manage||1 MB||13 Dec 2017 - 18:41||Main.TLaurin||Photo by Cascadia Iris Gardens|
|JPG||cristata6.JPG||manage||941 K||13 Dec 2017 - 18:43||Main.TLaurin||Photo by Cascadia Iris Gardens|
|jpg||cristata_edited-1.jpg||manage||44 K||01 Dec 2009 - 21:01||UnknownUser||Plate from Dykes' Genus Iris|
|jpg||cristata_flower_variations.jpg||manage||53 K||20 Sep 2010 - 20:29||UnknownUser||Pries photo|
|jpg||cristataalba.jpg||manage||25 K||10 Feb 2012 - 17:44||Main.htb||©2003 Laurie Frazer|
|jpg||cristatabudkp9.jpg||manage||71 K||05 Aug 2010 - 16:21||KentPfeiffer||Taken in my garden, zone 5b, on May 8, 2009|
|jpg||iriscrisata8.jpg||manage||330 K||26 Jan 2020 - 22:25||Main.TLaurin||Photo by Paul Black|
|jpg||iriscrisata9.jpg||manage||213 K||26 Jan 2020 - 22:23||Main.TLaurin||Photo by Paul Black|
|jpg||iriscristata16.jpg||manage||61 K||10 Oct 2013 - 20:24||Main.TLaurin||Photo by Alla Chernoguz-Ukraine|
|jpg||iriscristata17.jpg||manage||89 K||10 Oct 2013 - 20:26||Main.TLaurin||Photo by Alla Chernoguz-Ukraine|
|jpg||iriscristataalba01.jpg||manage||60 K||07 Oct 2014 - 02:44||Main.TLaurin||Photo by Kirsten Andersen-alpines.dk-Denmark|
|jpg||iriscristatabl01.jpg||manage||80 K||07 Oct 2014 - 02:47||Main.TLaurin||Photo by Kirsten Andersen-alpines.dk-Denmark|