1929, Iris Miraculosa

Addisonia volume 14, page 9, plate 453, 1929

IRIS MIRACULOSA

Native of southern Louisiana

Family Iridaceae, The Iris Family

To meet an iris in its native haunts, bearing strikingly beautiful flowers on stems reaching to the level of one's head is a rare experience, but we now know that it is to be expected in the lower Mississippi Delta. In March 1927 Ruth and Arthur Svihla collected and sent the writer a series of living specimens of such an iris, from one of which the accompanying illustration was made. The stature of the plant however, is not the only remarkable feature of Iris miraculosa, the flowers themselves being quite unusual. In the accompanying illustration only a lateral flower can be shown, as the terminal ones are unusually large. The perianth in this species is usually white, but colored forms like the one figured are occasionally met with. When and how the color was introduced in the course of the evolution of the species, may always remain a mystery, for it is a shade of lavender different from that in any other known American iris. But no doubt many colors, shades, and forms of irises were lost during the elevations and depressions, floods and droughts of the Tertiary Period and the alternate cooling and warming of the climate during the glacial epoch.

The direct or indirect ancestors of this species must have been harbored in the highlands during the latest general submergence of the continent. Then, however, the rigors of the ice age pushed it south almost to the limit of the land and into some of the most recently naturally laid-down alluvium of North America, and it never regained its lost territory.

Plants of Iris miraculosa are hardy at The New York Botanical Garden with the moderate protection of the cold-frames. A plantation of several dozen plants came through the winter of 1928, unscathed, with but slight protection, but curiously enough, only one plant flowered, whereas all the other Louisiana material flowered profusely.

Iris miraculosa is not restricted to one kind of habitat, but it thrives in several types and apparently equally well. Its requisite is a rich alluvium. This may be in the open with a carpet of a turf of grasses and small herbaceous plants or in the dense shade in

a swamp with cypress trees and various clustered shrubs. The type specimen is in the herbarium of The New York Botanical Garden. The giant iris has a very stout fleshy branching rootstock. The leaves are usually three to six together at the base of the flower-stalk. The blades are broadly linear-ensiform, mostly one to one and three-quarter inches wide, bright-green and often glaucescent. The flower-stalk is erect, three to six feet tall, stout, usually with three or four flower-bearing nodes below the terminal, the internodes somewhat flattened, angled below the base of the foliaceous bracts. The involucre is erect, of two or three bracts, the outer bract linear-attenuate, exceeding the flower, slightly scarious on the keel and the edges, the inner (second) bract equalling the lower part of the perianth, scarious margined. The flowers are usually two together at the tip of the flower-stalk and single or paired in the axils of the leaf-like bracts below. The hypanthium surrounding the ovary is shorter than the pedicel, sharply six-angled, together with the pedicel tightly enveloped in the involucre. The flower-tube is slightly dilated upward, slightly shorter than the ovary, six-ridged, the ridges in pairs. The three sepals are remate, three and a half to four and three-quarter inches long, arching. The claw is broadly linear, somewhat narrowed at the base; without, light-green and darker-green striate; within, yellow-green and with deeper-green striations on both sides of the median prominent ridge. The blade is broadly elliptic or elliptic-obovate, somewhat longer than the claw, mostly rounded or slightly notched at the apex; without, green at the base, dull lavender above; within, mainly lavender, deep-lavender about the margins, paler in the center and about the golden papillose crest which extends half way up into the blade, crenate above the middle or sometimes all around. The three petals are spatulate, nearly or quite as long as the sepals. The claw is cuneate, merging into the blade; without, greenish at the base, lavender and green-striate above; within, green-striate near the base, lavender on the margins. The blade is slightly broadened upward, more or less notched at the apex; without, rather pale lavender, with few green lines; within, bright-lavender, with few greenish lines. The three stamens are an inch and a half to two inches long. The style-appendages are half -ovate, about three-quarters of an inch long, incised-serrate, usually slightly acuminate. The stigma is two-lobed. The capsule is oval or obovoid, about two and a half inches long, bright-green, sometimes glaucescent, turgid, obscurely six-lobed, the ridges and grooves obscure. The seeds are numerous, in two rows in each cavity, usually between a half and three-quarters of an inch in diameter, irregularly half -orbicular, unevenly thickened, brown, corky-walled.

John. K. Small.


for more information on historic Irises visit the Historic Iris Preservation Society at

-- BobPries - 2014-12-10
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