1927, Iris Pseudacorus

Addisonia page 3, Plate 386, 1927

IRIS PSEUDACORUS
Yellow-flag
Native of Europe, adjacent Asia, and Africa
Family Iridaceae Iris Family

The great majority of our wild flags are natives. In this group of plants immigrants are few. Only three species have been recorded for North America, two from Europe, Iris germanica, and I. Pseudacorus – here illustrated – and one from Asia, I. orientalis.
The subject of this note also grows naturally in western Asia and northern Africa. These three species, all with vigorous rootstocks, which are extensively cultivated as ornamentals, are likely to survive, take hold, and permanently establish themselves when and where, as surplus plants, they may be thrown out of gardens or left on abandoned homesteads. The numerous seeds produced will also help further to disseminate the plants thus established. That this flag, naturally accustomed to wet habitats, thrives almost equally well in dry gardens, was noted long ago, for the herbalist Gerard, in the sixteenth century, records that "although it be a water plant of nature, yet being planted in gardens it prospereth well."
There is evidence that this plant, so widespread, found its way into the domestic economy of our rather recent semi-barbaric ancestors. Moreover, early in the past century it was recorded that: "The juice of the fresh root is excessively acrid, and has been found to act as an aperient, . . . The fresh roots have been mixed with the food of swine bitten by a mad dog, and they escaped the disease, when others bitten by the same dog died raving mad.

The root loses most of its acrimony by drying . . . the roots are used to dye black; and in Jura they are boiled with copper as to make ink. A slice of the fresh root held between the teeth removes some kinds of tooth-ache." The leaves are used as fodder and the brown seeds furnish a coffee-substitute. When mixed with our native cat-tails, bur-reeds, and sedges, it adds much to the attractiveness of the natural plant association. The flags of eastern North America lack yellow. Hence a plant exhibiting the shades of yellow possessed by this iris is a welcome addition to our flora. It is now established in the Atlantic States north of Florida. The specimens from which the illustration was made were found in the swamps of the excavation for the one time proposed Jerome Park Reservoir, Borough of the Bronx, New York City.

The yellow flag has a stout extensively spreading rootstock. The leaves are erect but more or less arching and nodding at the tip, linear-attenuate, bright glossy green, mostly three quarters of an inch wide. The flower-stalk is two to three feet tall, rather stout, green, usually with one or two relatively short leaves or leaf -like bracts. The flowers are solitary or two together terminating the flower-stalk, and often in the axil of the upper leaf. The involucre subtending the flower has two main bracts neither of which exceeds the flower. The pedicel is about as long as the hypanthium at anthesis, not exserted beyond the involucre. The hypanthium surrounding the ovary is bluntly three-angled, green. The perianth-tube is cylindric-campanulate, about half as long as the ovary. The three sepals are two to three inches long, arching. The blade is suborbicular, oval or ovate, yellow, faintly striate, with lines and flecks of brown at the base, or the brown sometimes exaggerated into a blotch. The claw is broad, but with involute edges, much shorter than the blade, yellow and streaked and flecked with brown. The three petals are yellow, often pale, three quarters of an inch to fully an inch long, linear to linear-pandurate, obtuse. The three stamens are an inch to an inch and a quarter long. The filaments are white or nearly so. The anthers are pale yellow, shorter than the filaments. The three style-branches are about one and a half inches long, narrowly cuneate, but relatively broad, yellow, paler near the base than above. The style-appendages are obliquely ovate or somewhat triangular, more or less recurved, irregularly toothed and sometimes slightly incised. The stigma is entire. The capsule is cylindric-prismatic or somewhat ellipsoid, two to three inches long, bright green, often shining, turgid, bluntly three-angled, longer than the pedicel. The seeds, in one row in each capsule-cavity, are suborbicular or somewhat angular from pressure, corky, about a quarter of an inch in diameter or slightly longer.

John K. Small

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

-- BobPries - 2014-12-08