Rue Anemone is a native erect perennial forb growing 4 to 8 inches high on smooth slender stems.
The leaves are compound, both basal and on the stem. Basal leaves are stalked, 2 to 3 times parted, each leaflet distinct, stalked, rounded, with teeth (lobes) toward the tip. Basal leaves rise directly from a cluster of three or four elongated tubers. These leaves have a smooth surface with a fine network of veins and are green to purplish-green in color. Stems leaves resemble the basal leaves but can be stalkless. There is usually a pair of 3-parted involucral bracts under the inflorescence which appear opposite each other forming a whorl and when stalkless they appear to be 6. These are bracts and not true leaves. Bracts are longer than wide and usually with 3 blunt lobes.
The inflorescence is a few-flowered (1 to 5 flowers) loose cluster (umbel shape) rising above the whorl of stem leaves. The umbel shape makes this species unique in the North American Thalictrum genus.
The flowers are very delicate looking, 3/4 inch wide, on slender stalks, without petals but with the 5 to 10 showy sepals ranging in color from white to pinkish. The stamens number 7 to 30, with white filaments and yellow anthers. These are shorter than the sepals. Pistils are numerous.
Seed: Fertile flowers produce from 8 to 12 1/3 inch long dry achenes with prominent veining (8 to 10) on the sides.
Habitat: Rue Anemone grows from a black tuberous root system, preferring loamy soil but not too much moisture - mesic to dry conditions with dappled sunlight. It will be found near wood edges, thickets, river banks. Re-seeding is the primary means of spreading. After flowering, it can have more shade when the upper tree canopy leafs out.
Names: The genus, Thalictrum, was originated from the Greek word 'thaliktron' by the Greek pharmacologist Dioscorides, who used it to describe plants with divided leaves. Likewise, the species name, thalictroides, is a reference to divided leaves of this plant. The name Anemone, is obscure but is generally applied to what are called windflowers, and is thought by some to be from the Greek anemos, meaning 'wind'. But the studied opinion (see Stern, Ref.#37a, and Ref.#W7) is that consideration must also given to the god Adonis, who in the Greek myth was killed while hunting a boar and from his blood came a red windflower [Anemone coronaria] and the name is a corruption of an old Semitic word for Adonis.
Many references still classify Rue Anemone as Anemonella thalictroides based solely on the inflorescence but Flora of North America maintains - "The leaflets, flowers, and fruits, however, are not unlike those of Thalictrum." Minnesota authorities follow Flora.
The authorship of the plant classification is as follows: The first to classify was 'L.' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. He named the plant Anemone thalictroides. His work was amended and the name changed by several people, the last being ‘Eames’ which refers to Edwin Hubert Eames, M.D. (1865-1948), American Medical Doctor and botanist, co-founder of the Connecticut Botanical Society, member of the New England Botanical Club and as George Torrey stated “the leading amateur collector in the state.” His plant collection of over 100,000 specimens became the basis of the Torrey Herbarium at the University of Connecticut. The plant was then called Anemonella thalictroides. Later, in 1957, the name was changed to Thalictrum thalictroides by (and based on his work) ‘B.Boivin’ which refers to Joseph Robert Bernard Boivin (1916-1985), Canadian botanist who worked at the National Museum of Canada, Harvard and Dept. of Agriculture in Ottawa. His PhD thesis was on the genus Thalictrum. Some botanists have resisted this change but Flora of North America has a rebuttal to their argument.
Comparison: The plant often confused with Rue Anemone is "False Rue Anemone" Enemion biternatum. There the leaflets are also in 3's, but the whorls are lacking and the leaflets are more deeply lobed and have a glandular leaf tip. The flowers are 5-parted and produce a seed follicle containing several seeds, not dry achenes. See also the Wood Anemone, Anemone quinquefolia.
Above: 1st photo - The flower (or flowers) above the whorl of involucral bracts. Note the numerous stamens and pistils. 2nd photo - The sepals have the color. There are no petals.
Below: Involucral bracts appear just beneath the inflorescence and when paired opposite each other appear whorled. If the compound bracts are stalkless, it looks like 6 separate lobes. Bracts are longer than wide and usually with 3 blunt lobes. Stem leaves may occur further down the stem.
Below: 7 to 30 stamens with yellow anthers surround a cluster of numerous pistils in the center of the flower.
Below: 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. Illustration courtesy USDA
Notes: Rue Anemone is indigenous to the Garden area. Eloise Butler catalogued it on May 25, 1907. Martha Crone planted it in 1946, 47, and '48. It has been listed on all later census reports. It is native to the dry open woods of the SE counties of Minnesota, extending up through the metro countries. It is native to most of the U.S. from the longitude of Minnesota eastward, but in Canada, only in Ontario. In Eloise Butler's day the accepted scientific name was Anemonella thalictroides.
On of the oddities concerning this plant was Martha Crone's receipt on June 14, 1951 of a double Rue Anemone “in coffee can from Mrs H. S, Olson, 302 So. D. St., Lake Worth, Florida, found at Wacouta near Red Wing in 1923.” And then in 1952 Martha also located Rue Anemone doubles while on her field trips - two on May 19 near Fletcher MN and 10 on July 31 at Red Wing MN. These have not survived.
There are 5 species of the genus Thalictrum found in Minnesota - four are meadow rues -T. dioicum, Early Meadow Rue; T. dasycarpum, Tall Meadow Rue; T. revolutum, the waxy-leaf meadow-rue (from northern MN and is considered quite rare, if still present), and the Veiny Meadow-rue, T. venulosum, which is also found in the Garden. The fifth species is the Rue Anemone. Subspecies are not recognized.
Eloise Butler wrote: "The Rue Anemone of oak woods has a cluster of bright pink flowers on stalks set like the sticks of an umbrella above a whorl of leaves. Another leaf, similar to that of the false rue anemone, arises directly from a cluster of three or four fleshy roots like miniature sweet potatoes." Published May 21, 1911 Minneapolis Sunday Tribune (read full article)
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"