Minnesota Dwarf Troutlily is a native perennial ephemeral of the early spring woods, this is the least seen of the three Minnesota species of troutlily (or Dog-tooth Violet as they are also known).
Leaves: This species has lanceolate leaves, up to 5 inches long. Like the other troutlilies, the leaves are mottled green with some reddish-brownish overtones and all are basal. Non-flowering plants have one leaf and flowering plants usually have two.
Flowers: The flower stalk (a scape - an above ground extension of the underground stem) arises between the basal leaves The stalk can be 1-1/2 to 5 inches high. Each flowering plant has a single flower with 4 to 6 petal-like tepals (although 5 is normal in this species) that are usually more pale pink than white, and only about 1/3 inch long. The tepals can strongly reflex but are usually seen with only an outward spreading of the tips. The flower has from 2 to 6 stamens (6 is normal in other Erythronium) with white filaments, yellow anthers, yellow pollen and a white un-lobed style. Many plants in a grouping will flower annually.
Seed: This species is not known to produce a seed capsule [University of Minnesota Plant Conservation.] and when it does it is usually the result of a cross with the White Troutlily (E. albidum). This failure to produce seed may result in extinction if habitat cannot be maintained although the normal method of propagation is by bulblet offshoot.
Habitat: The most common habitat for this plant is a wooded floodplain or north facing slopes that are moist. Spring dappled sunlight is desired but shade from the over-story must be provided in summer. It propagates from an offshoot from the stem just below ground level from which a single bulblet is to be produced. This offshoot is above the existing bulb which is distinguishing for this species.
Comparison: E. propullans' close relative is the White Troutlily, E. albidum, for which it is easily mistaken when not in flower. The distinguishing differences are: E. albidum has longer and wider leaves and larger flowers with 6 tepals; you will see mostly leaves and only a few flowers because that species has a very low annual flowering rate; and finally E. albidum produces 1 to 3 bulblets from the end of an offshoot below or lateral to the current bulblet. These two plants, when in close proximity, tend to hybridize and the resulting plants generally look like E. albidum. Plants die back in early summer.
Names: The genus, Erythronium, is Greek and taken from a similar European species. The word is derived from ěrythrŏs, meaning 'red', referring to the mottled spots on the leaves. The species name, propullans, means 'to sprout forth' and refers to the way the new bulblet arises from the flowering stem just below ground level. The author name for the plant classification ‘A.Gray’ refers to Asa Gray (1810-1888), American botanist, Professor of Natural History at Harvard and instrumental in unifying plant knowledge of North America and author of Gray’s Manual - Manual of the Botany of the Northern United States, from New England to Wisconsin and South to Ohio and Pennsylvania Inclusive.
Above: The flower of MN Dwarf Troutlily, only 1/3 inch long; stamens have yellow anthers and there is a single style.
Below: A pair of the early spring flowers. Second photo - an ovoid 3-chambered seed capsule with the remains of the style attached. Capsules are the result of hybridization with the White Troutlily as the true plant does not set seed.
Below: For comparison- the White Trout-lily, in the second photo, has larger flowers and leaves and also has 6 petal-like tepals. The Dwarf Troutlily (first photo) is much smaller with 5 tepals.
Below: A new flower bud against the background of the mottled leaf.
Below: A historical photo of the Minnesota Dwarf Troutlily, from a Kodachrome taken in the Garden by Martha Crone on April 25, 1955.
Notes: Minnesota Dwarf Troutlily is quite rare and was first identified in 1871 when Faribault teacher Mary Hodges sent a collected example to Professor Asa Gray at Harvard. He determined it was a previously un-recorded species and gave it the botanical name it has and presented a specimen of the plant to the Kew Herbarium in London the same year. The Minnesota DNR's plant survey has identified only three counties in Minnesota where the plant has been collected - Goodhue, Rice and Steel. They exist only in the ravines of an area around the Straight, Canon, Little Cannon and North Zumbro Rivers. This is the only known population in North America.
Scientific Study: Considerable scientific knowledge was accumulated in a Master's Thesis by Jo Ann Banks in 1978 at the University of Wisconsin. Read it here -11.7mb file). A significant finding of her paper is that habitat loss in this restricted area could easily result in extinction of the species.
Eloise Butler first recorded planting this plant on May 17, 1909 in the north end of the wetland. She obtained specimens from a source near Cannon Falls which is in Goodhue County and remarked in her log - "Poor material, probably will not grow." Martha Crone planted 175 of them on April 18, 1946 and more in 1955 without listing her source, but Martha was quite familiar with plant locations in those three counties where they are native. The plant was listed on Martha Crone's 1951 Garden Census and on all the subsequent census of Garden plants.
Endangered: Minnesota Dwarf Troutlily is currently listed on the Minnesota DNR list of endangered species. It is also the only Minnesota plant species on the Federal endangered list. There is also a good introduced representation at the Minnesota Landscape Arboretum.
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.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"