Bindweed vines usually have showy flowers with triangular outline leaves. Hedge Bindweed is a native perennial vine that can be partially erect but needs to climb on something as the vine can grow to ten feet. Stems will be green to reddish-green and either angled or ridged. This vine, like all true bindweeds, twines counterclockwise.
The leaves are triangular, half again as long as broad, with a pair of auricles at the base which can often form an arrowhead shape or a rounded-off base to the leaf. The leaf stalk is at least half as long as the mid-leaf vein or longer. Slightly different forms of leaf will be found on the same plant.
The inflorescence is a slender flowering stalk, rising from a leaf axil, carrying usually only one bud. These can occur at several places along the stem.
Each flower has a funnel shaped white corolla (can be pinkish or with a pink tinge as photo below shows), formed by 5 united shallow lobes. The lobe edges are a bit ragged and flare outward making the open flower a trumpet shape, 2-1/2 to 3 inches wide and 1-1/2- to 2-3/4 inches long. The inside base of the corolla has a yellow throat and deep inside are the 5 stamens and the pistil with a divided white style. The stamens are tightly appressed around the style. The calyx at the base of the flower is much smaller, has 5 sepals of about equal size; there are 2 large green bracts at the base of the calyx that hide the sepals from two sides and sort of form a cup. This is a distinguishing characteristic of the genus.
Seeds are brown and ovate shape about 5 mm across.
Habitat: You will find Hedge Bindweed in moist to slightly dry meadows and disturbed places. It grows from a rhizome and fibrous roots and prefers full sun. Long tongued bees are the primarily pollinators. The flowers close during dull weather, but not for a shower.
Names: In earlier years Hedge Bindweed was classified as Convolvulus repens, then as Convolvulus sepium. The move of the plant from the old genus Convolvulus, into Calystegia, separates those plants that do or do not have the cup-like bracts at the base of the calyx. The genus name, Calystegia, is from the Greek and means "covered cup" referring to the bracts covering the bottom of the calyx. The species, sepium, refers to plants growing in hedges or used for hedges.
The accepted author names of the plant classification are: First to classify in 1753 under the name Convolvulus repens was '(L.)' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. His work was amended by ‘R.Br.,’ which refers to Robert Brown (1773-1858), Scottish botanist for whom ‘Brownian motion’ is named, and who provided names and descriptions of various plant families and was the first keeper of the Botanical Dept. of the British Museum.
The parts of the various other common names relate to the plant commonly being found in hedges in the Old World; it looks like a morning glory; the bracts at the base of the calyx which cover it and the entire bud before flowering lead to 'hooded'; 'False' is more obscure as the plant is a bindweed, but perhaps it has to do with the counterclockwise twining, which is 'false' compared to other vines, but not to the bindweeds.
Comparisons: Do not confuse this plant with the smaller Field Bindweed, Convolvulus arvensis. See comparison below. Another similar plant is Low Bindweed, Calystegia spithamaea, which has similar flowers but only grows to 20 inches and has a more oblong leaf. Another plant that is not a vine but has large trumpet white flowers is the poisonous Jimsonweed, Datura stramonium, but it is rarely found in the wild in Minnesota.
Above: Flowers occur from late June onward depending on the season; these of early to late July. The inflorescence is a single stalked flower rising from a leaf axil at various point along the stem. 2nd photo - The stamens are tightly appressed around the style.
Below: 1st photo - Note the two large bracts that enclose and hide the calyx. They also hide the flower when in the bud stage, which led to one of the old common names of "Hooded Bindweed". 2nd photo - The triangular shape leaf with squared off base. The rest of the leaf may vary in appearance - sometimes being ovate.
Below: 1st photo - This vine is twining around various grasses to gain support and height. Note the counterclockwise rotation. 2nd photo - From the axil of this new leaf will arise the stalk of the flower. The flower stalk of Hedge Bindweed is more than half as long as the leaf mid vein. This distinguishes the plant from the similar but shorter, Low Bindweed, C. spithamaea
Below: Hedge Bindweed will also be found with this wonderful pink banding to the outer edge of the petals.
Below: A comparison of Hedge Bindweed (on the left in both photos) and Field Bindweed, C. arvensis, (on the right in both photos). Hedge Bindweed is much larger in width and length and Field Bindweed does not have the large cup-like bracts surrounding the calyx.
Notes: Eloise Butler first introduced Hedge Bindweed to the Garden in Sept. 1909 and more plants in 1925. It was listed on Martha Crone's list of Garden plants from 1951 as Great Bindweed. This plant is considered to be native to the state by the Minnesota DNR. It is found in most Minnesota counties with widely scattered exceptions and in all of North America except the very far north Canadian Provinces. Several states in the south have considered it a noxious weed.
Varieties: The literature lists 7 different subspecies of which two are reported in Minnesota - subsp americana. and subsp. angulata. The DNR does not track subspecies in the county survey database. For general identification purposes, these are not important as they concern slight regional differences in North America, especially in the corolla color, the size of the cup bracts and any angles on the leaves. Some authorities believe these are regional ecotypes and should not be separated into subspecies.
Eloise Butler had an appreciation for the plant and wrote: "A Wild Morning Glory, Convolvulus sepium is everywhere present, running over waste places and doing good service by concealing unsightly objects with its lovely large flowers of pale pink or white, and making dense tangles in the woods, which, in the struggle to break through, forcibly impress one to rename it bindweed. Being common and a weed, it is not properly appreciated. It might be improved and varied by cultivation, and it would outrank its relative, the tame morning glory, Ipomaea, as a porch vine, for it is a perennial and can always be depended upon to furnish shade. A certain piazza in Nova Scotia, decorated with a long established specimen of bindweed, is admired by all who see it." Published Sept. 17, 1911, Minneapolis Sunday Tribune. [Read entire 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"