Cut-leaved Toothwort is a native perennial forb growing 8 to 16 inches high on an erect unbranched stem.
The leaves are both basal and stem and both look similar. The basal leaves rise on stalks directly from the rhizome. The leaf is 3-parted, each leaflet without a stalk. The terminal leaflet is oblong to lanceolate to linear in shape with toothy margins or it can be 3-lobed which can deceive you into thinking it is a 5-parted leaf. Lateral leaflets are similar but smaller. Basal leaves usually form right after flowering time. The stem leaves (usually 2 or 3) are of similar design to the basal leaves, are stalked, but usually appear in a whorl or opposite each other if only two, near the top of the stem. Leaf stalks, the main stem and the flower stalks usually will have some fine hair.
The inflorescence is a terminal raceme, rather loosely organized of stalked flowers, without bracts. The raceme elongates as flowers open, typical of Mustard family plants.
The flowers are 4-parted, are up to 3/4 inch long, with a tubular calyx that has 4 light green oblong sepals with obtuse tips. The four petals are white to pinkish, much longer than the sepals and have rounded tips. The reproductive parts include six stamens where two inner pairs have filaments (white) longer than an outside pair. Anthers are yellow. There is a single style with a globose shaped stigma.
Seed: Mature flowers produce a linear dry pod (called a silique), usually ascending, that contains oblong brown seeds. The pod splits open with a twist to eject seeds. Toothwort seeds usually require at least 60 days of cold stratification for germination.
Habitat: Cut-leaved Toothwort grows from a horizontal segmented rhizome which spreads producing colonies of plants. It can also re-seed. It requires moderate moisture levels, rich soils such as in woods, woodland edges. Full to partial sun is needed up to flowering, then partial to full shade for the summer. Located in the Woodland Garden in many places.
Names: "Toothwort" refers to the rootstalk which has teeth-like segments that resemble a string of beads. The species name concatenata, meaning "linking together", and refers to the rhizome appearance. Botanists have recently placed this plant into the genus Cardamine instead of the former Dentaria where it was called Dentaria laciniata. Cardamine is derived from the Greek kardamon, the Greek name for a certain cress (also in the Mustard family).
The author names for the plant classification are as follows: First to publish was ‘Michx.’ which refers to Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloging many species. Two important works of his are the Histoire des chênes de l'Amérique septentrionale (1801 - Oaks of North America), and the Flora Boreali-Americana (2 vols., 1803). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva, for which Thomas Nuttall provided some supplements. Michaux's work was updated by ‘Small’ which refers to John Kunkel Small (1869-1938), American Botanist, first curator of the New York Botanical Garden, best known for Flora of the Southeastern United States.
Comparisons Cut-leaved Toothwort has similar appearing flowers to C. diphylla, the Two-leaved Toothwort but on that species the leaflets are lobed with coarse dentations not deeply cut into palmate divisions and the stem leaves are only 2 appearing opposite each other. It usually does not set seed in the silique and the rhizome is unsegmented.
Above: 1st & 2nd photos - Six stamens are in pairs with one pair shorter than the other two. The yellow-green stigma has a globose tip. 3rd photo - The 4 light green oblong sepals have obtuse tips and are much shorter than the petals.
Below: 1st photo - Buds of late April. Note the long stalks on the stem leaves. 2nd and 3rd photos - Pairs of 3-parted leaves. Each leaflet stalkless and each leaflet can be 3-lobed as seen here, most lobes with marginal dentations.
Below: The thin seed pod, known as a "silique" is typical of the Mustard family of plants.
Below: A root of a young plant, showing the beginnings of the segmentations of the rhizome.
Notes: Cut-leaved Toothwort is not indigenous to the Garden but native to the area. Eloise Butler's records show that she obtained plants of this species on April 28, 1912 from a "Mrs. Commons' " farm in Minnetonka, MN. Martha Crone planted specimens in 1933 on May 15th. It is native to the Minnesota woods of the SE, the Metro central and partially in the NE. The plant has an extensive range in the U.S., covering the entire eastern 2/3rds as far west as the Dakotas down to Texas. It is known in Canada in Ontario, Quebec and New Brunswick.
The other variety of Toothwort in the Garden is the Two-leaved Toothwort, Cardamine diphylla, which is not native to Minnesota. There are 6 native species of Cardamine found in Minnesota: C. bulbosa, Spring cress; C. concatenata, Cut-leaved Toothwort; C. impatiens, Narrowleaf Bittercress; C. parviflora, Small-flowered Bittercress; C. pensylvanica, Pennsylvania Bittercress; and C. pratensis, Cuckoo Flower. Some sources include C. diphylla but the U of M reports there are no collected specimens. C. pensylvanica is also found in the Garden.
During the years Ken Avery was Gardener (1959 to 1986) he reported Cut-leaved Toothwort has bloomed in the Garden as early as April 12 and as late as May 7th, but in 1987 Gardener Cary George reported it bloomed earliest - April 9th.
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"