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Plants of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

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Common Name
Dwarf Crested Iris

 

Scientific Name
Iris cristata Aiton

 

Plant Family
Iris (Iridaceae)

Garden Location
Historical - not extant

 

Prime Season
Late Spring Flowering

 

 

Dwarf Crested Iris is native to the Eastern and Southeastern parts of the U.S. The plant grows from 6 to 9 inches high with solid stems.

Leaves are narrowly sword shaped. Most are basal, usually 6 to 8 with lower ones sheathed with brown blades, the upper 4 or 5 green to yellow-green, not sheathed, up to 6 inches long, slightly curved and not prominently veined. These increase in length after flowering. with a raised (thickened) mid-rid, not prominently veined. The flower stem may also have 2 to 3 leaves.

The inflorescence consists of 1 or 2 flowers, at the top of a solid stem that rises from the root. Stems may have some 1 or 2 stem leaves. The upper section of the stem under each flower forms a greenish spathe covering the ovary of the flower. Stems are quite short, just reaching the tops of the leaves. Blooms are usually in mid to late May in Minnesota, depending on the early or late onset of Spring.

Flowers are about 1-1/2 to 3 inches wide when fully open; the perianth being blue, lilac-purple or white. The tube of the perianth widens as the flower opens. The 3 outward spreading drooping sepals (also called 'falls' in Iris terminology), which surround the true flower, each have 3 parallel, toothed, crested ridges on a white patch, tinged with gold, known as a 'signal,' which has a purple border, the sepal then tapers to a clawed (extremely narrowed) base. [In a "bearded" iris, this crest is replaced by the beard] The petals (called 'standards' in the Iris genus) are smaller than the sepals and curve upward and outward between the sepals such that from above both sepals and petals look like 6 spokes of a wheel. Petals are the same color with smooth margins.

The fruiting parts are in the center of the flower. The style forms flat petal like branches, usually called 'style arms' that are narrowly triangular and that reflex outward atop the base of the sepals and cover the anthers and sigma, providing rain cover for the pollen. The nectar of the plant is in glands at the base of the petals. The ovary, in the top of the spathe is 3-celled and triangular.

Fruit: Seed capsules are sharply 3-angled outlining the three inner chambers of ovary and the capsule remains within the spathe. Each chamber of the capsule usually has two rows of seeds, which are yellowish-brown at maturity, smooth, with a narrow white appendage wrapped around the seed. These are distributed by wind when the capsule opens.

 

Habitat: The plant spreads via branching rhizomes which have fleshy roots; it forms clumps as the rhizomes separate and the plant can rapidly spread. In its native habitat it is found on rocky wooded slopes, on bluffs and along streams, calcareous soil preferred with full sun to partial shade. The plant tolerated dry periods.

Names: The genus name, Iris, is after the Greek goddess of the rainbow. The species cristata means 'crested' or having 'tassel-like tips', all referring to the crests of the flower. The author name for the plant classification - ‘Aiton’ is for William Aiton (1731-1793), Scottish botanist, who succeeded Phillip Miller as superintendent of the Chelsea Physic Garden and then became director of Kew Gardens, where he published Hortus Kewensis, the Garden’s catalogue of plants.

Comparison: The most similar iris is the Dwarf Lake Iris, Iris lacustris, found in regions around the Great Lakes. The two are very similar and a recent paper by GARY L. HANNAN AND MICHAEL W. ORICK indicates that the I. lacustris emerged from the gene pool of I. cristata after glaciation. [American Journal of Botany 87(3): 293–301. 2000.] The other two iris remain in the Garden today are Blue Flag, Iris versicolor L. which is a our native marsh iris that is indigenous to the Garden, and the introduced Yellow Flag, Iris pseudacorus .

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

Pair of plants drawing

Above: Plants are very short with the flower stem held at or just above the leaves. Drawing from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.

Below: 1st photo - each sepal (known as a 'fall') has a ridged (the 'crest') patch of white (the signal) with gold trimming and bordered with deep purple. 2nd photo - leaves are sword shaped with the lowest leaves sheathed and the upper leaves green.

sepal fall leaves

Below: This view from above shows how the more upright petals are placed between the reflexing sepals and the lighter colored style arm covers part of the crest.

view from above

Below: This view shows the lighter color flat branches (style arms) poised over the crest of the sepal covering the reproductive parts.

two flowers

Notes:

Notes: Dwarf Crested Iris is not native to Minnesota, but to a section of the United States east of the Mississippi River in unglaciated regions, to the east coast and south of Iowa, Wisconsin and Michigan. Absent along the Gulf Coast. It was introduced to the Garden by Eloise Butler in 1928 when she obtained plants from Mr. Burgess' Nursery in Askov MN. Then Martha Crone planted 20 in 1947, plants sourced from Henderson's Nursery in Greenburg Indiana; 10 more in '51 from the Robbins Blue Ridge Nursery, and in '56 she added 100 from The Three Laurels Nursery in Marshall North Carolina. Cary George replanted it in 1994 when he received it, and some other plants, as gift from the National Parks Convention which met in Minneapolis that year.

There are three species of wild Iris found in Minnesota. The introduced I. pseudacorus, Yellow Flag and two native species - I. versicolor, Blue Flag (or Northern Blue Flag), and I. virginica, Southern Blue Flag, which is found only in the SE quadrant of the state.

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

graphicIdentification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.



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