''Iris virginica'', with the common name Virginia blueflag,
Virginia iris, great blue flag, or southern blue flag, is a
perennial species of
flowering plant in the
Iridaceae (iris) family, native to central and eastern North America.
It was identified as a separate species by
Edgar Anderson, and is one of the three ''Iris'' species in Anderson's
''Iris'' flower data set, used by
Ronald Fisher in his 1936 paper "The use of multiple measurements in taxonomic problems" as an example of
linear discriminant analysis
Linear discriminant analysis (LDA), normal discriminant analysis (NDA), or discriminant function analysis is a generalization of Fisher's linear discriminant, a method used in statistics and other fields, to find a linear combination of features ...
.
Description
''Iris virginica'' is a perennial plant that grows up to tall. The plant's sword-shaped basal leaves are erect or sometimes arching and measure up to long and across at the base. The leaves have smooth margins and are bluish green to green and
glabrous. Unbranched or sparingly branched flowering stalks rise from the basal leaves to a height of up to . Small, alternate leaves are located on the stalks, with 1 to 2 flowers emerging from the axil of each of these leaves on
pedicels that are long.
The flowers, which bloom May to July, are blue to blue-violet and are a typical iris shape. Each flower has 3 drooping
sepals
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
, called "falls", that have white marks and yellow near the throat, and 3 upright
petals, called "standards". Flowers measure across.
Distribution and habitat
''Iris virginica'' is native in the United States from Nebraska to the west, Florida and Texas to the south, New York to the east, and the Canadian border to the north. In Canada, it is native in Ontario and Quebec.
It grows in wet areas, sometimes in shallow water, including marshes, wet meadows, swamps, river bottoms, sloughs, ditches, bottomland prairies, edges of sinkhole ponds, and in shallow water.
Uses
The
Cherokee use this
medicinal plant for traditional medicinal uses. The root is pounded into a paste that is used as a
salve for the skin. An
infusion made from the root is used to treat ailments of the
liver, and a decoction of the root is used to treat "yellowish urine".
It may be one of the Iris species used by the
Seminole to treat "shock following alligator-bite".
''Iris virginica'' is one of three iris species in Ronald Fisher's
''Iris'' flower data set.
References
External links
Kemper Center for Home Gardening.org: ''Iris virginica'' (Virginia iris)
{{Taxonbar, from=Q7934335
virginica
Flora of the Southeastern United States
Flora of the Northeastern United States
Garden plants of North America
Plants used in traditional Native American medicine
Plants described in 1753
Taxa named by Carl Linnaeus
Flora of the North-Central United States
Flora of the South-Central United States
Flora of Eastern Canada