Fringed Black Bindweed is a native twining perennial vine that can grow to seven feet long. The stem is light green with reddish tints to fully reddish, slightly angular, with swollen nodes. Stems have fine hair. The vine freely branches and is either climbing on other plants or sprawling. It twines clockwise.
The leaves are alternate on the vine, large, well spaced and have heart-shaped bases; the blade can be oval to triangular. Stalks are long and slender and terminate in a sheath at the stem (an ocrea) that is cylindric and can be greenish-brown to reddish, with a base that has fine downward pointing bristles. The leaf stalk has backward slanting hair (retrorse). The leaf upper surface is without hair but the underside has fine hair. Margins are wavy and can have fine reddish hair-like projections (cilia). Leaf vein pattern is very conspicuous compared to Black Bindweed, F. convolvulus.
The inflorescence is a terminal spike-like arrangement, 3/4 to 4 inches long, along which are clusters (fascicles) of stalked flowers. These may rise from an upper leaf axil also. The stalk of the cluster usually has downward pointing hair (retrorse).
The flowers are very small, bisexual, 5-parted, about 1/8 inch long (1.5 to 2 mm) including the small stipe-like base, in groups of 4 to 7 at each fascicle of the inflorescence; they have a greenish-white perianth. The flower lacks petals and the sepals (here termed tepals) have the color. These have an elliptic shape with obtuse to acute tips arranged as 3 outer and 2 inner. Each outer tepal has a slight keel so that when the flower is closed it looks 3-angled. The inner two tepals are slightly smaller. There are 6 to 8 stamens, the anthers flattened at the base and three styles that are joined at the base, with the tips knob-like, rising from a 3-carpellate ovary.
Seed: Mature flowers form a dry black 3-sided achene that lacks wings and resembles a kernel of buckwheat - which is how a number of alternate common names using 'buckwheat' came about. The seed surface is shiny and smooth. The flower is pollinated by insects that reach for nectar secreted by the glands at the base of the stamens.
Habitat: Fringed Black Bindweed grows in dry woods and thickets with mesic conditions and full to partial sun. The full red color is attained in full sun. It is not rhizomatous but has a slender fibrous root system. It is considered threatened in some states.
Names: The genus Fallopia is an honorary named for the early Italian anatomist, Gabriele Fallopi (1523-1562). He was professor of anatomy at Pisa and Padua. The species cilinodis, is from the words “cilia” and “node” and refers to the slender hair at the leaf ocrea. A former synonym for this species was Polygonum cilinode and also Bilderdykia cilnodis. Fringed Black Bindweed was separated from the genus Polygonum and placed in Fallopia which describes erect or climbing or sprawling fibrous rooted annuals and perennials which have ocreas that are never 2-lobed at the tip and the outer tepals that are winged or keeled. Molecular data show the two genus are close and thus, some authorities have not accepted the change. Minnesota authorities have done so, following the lead of Flora of North America.
The author names for the plant classification are as follows: The first to classify 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, published posthumously and contained the description of this species using the name Polygonum cilinode ). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva. Michaux's work was amended in 1971 by ‘Holub.’ which refers to Josef Ludwig Holub (1930-1999), Czech botanist, Professor of Botany, co-founder of the Czech Institute of Botany and whose work centered on vascular plant taxonomy. He was the principal author of Flora of the Czech Republic and the Flora of Slovakia.
Comparisons: This is a vine unlike others in the Fallopia genus in that the others have ocreas that are without hair or bristles. The other members of the genus found in Minnesota - Fallopia convolvulus, Black Bindweed has seeds that are dull with a minutely granular surface. F. scandens, False Buckwheat, is similar, also having shiny seeds but the fruiting perianth has wings and the ocrea lacks the hair. The only other species in Minnesota is Japanese Knotweed, Fallopia japonica, an invasive introduced plant where the stems are erect and large. The clockwise twining also separates the Fallopia plants from the bindweeds in the Convolvulus genus where they twine counter-clockwise.
Above: The inflorescence. Each separate fascicle has 4 to 7 flowers. 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: Two views of the leaf sheath orcea with the fringed hairs. Note the retrorse hair on the stalks.
Below: 1st photo - an example of a plant climbing on a host. 2nd photo - the upper side of a typical leaf.
Below: 1st photo - the underside of the leaf with paler color and fine hair. 2nd photo - detail of a flower showing the stamens with anthers flattened at the base and the styles united near the base but with stigmas separated.
Notes: Fringed Black Bindweed is a native perennial found in 20 counties of Minnesota, all located in the North and Central part of the State, generally not south of the Metro area. Metro area counties where it is known are Hennepin and Ramsey. It is not indigenous to the Garden but has been noted on both the 1986 and 2009 census reports.
As it does not grow well in hot, humid, or very dry conditions, in North America Fringed Black Bindweed is found in most of the lower Canadian Provinces and in the U.S. in states east of the Mississippi River but not in the warmer and more humid states of the far south. Minnesota is at the western end of its range in the U.S. where it is found east of Minnesota but not south of Minnesota. There are eight species of Fallopia found in North America, twelve world-wide.
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"