Field Bindweed is an introduced and invasive twining perennial vine growing with stems to 3 feet long. New parts of the stem may have hair, otherwise it is smooth, green to reddish in color. The vine, like all true bindweeds, twines counterclockwise.
The leaves are alternate, 2x as long as wide and usually arrow-shaped with 2 descending lobes at the base, between which is the slender stalk. Margins are smooth, the upper surface a dark green, veins curving toward the tip from the mid-vein and fine reticulation between the main veins.
The inflorescence consists of a slender flowering stalk arising from a leaf axil that may have 1 to 4 flowers, but commonly 2. When paired, one stalk will be shorter than the other and only one bud will flower at a time.
The flowers have a funnel shaped corolla with 5 lobes that are united with very shallow joining lines between the lobes that look more like wrinkles in the white corolla. The corolla can also be pinkish or with pinkish tinge that separates the lobes. Flowers are 1 to 2 inches long and half as wide when open. There is a small patch of yellow at the base of the throat of the corolla from which rises the 5 stamens and pistil which has a divided white style. At the outside base of the corolla are 5 much smaller green sepals, mostly equal in size, and below them on the flower stalk are a pair of small green bracts. There are no cup shaped bracts at the base of the calyx like there are on the bindweeds of the Calystegia genus.
Seed: Fertile flowers produce a rounded seed capsule containing 4 dark keeled seeds (rounded on one side, forming a wedge with other 2 sides) that have a pebbly surface.
Habitat: Field Bindweed takes hold in waste places, disturbed ground, path edges where it is not overshadowed by larger plants, growing well in poor soils and dry conditions in full sun. It will sprawl when it does not have another plant to climb on. It grows from a taproot and rhizomatous root system and thus spread vegetatively. The roots are brittle and easily leave a portion in the ground when you try to remove the plant. These will easily create a new plant. See notes below for more information.
Names: The genus Convolvulus, is from the Latin convolvo, meaning 'to intertwine' as the plant must wrap itself around another small object to spread, as it has no tendrils. It has been observed that a plant can make a complete twining revolution in about 1.5 hours. The species, arvensis, is from the Latin arvum, 'a cornfield' which is where farmers in Europe frequently encountered this plant and now arvensis is commonly applied to plants that make there home in areas that are or are like fields. The author name of the plant classification, 'L.,' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. The other alternate common names are all older terms which refer to the ability of the plant to quickly spread. 'Creeping Jenny' is, unfortunately, a very commonly used older name for a number of plants that creep.
Comparisons: There are several other bindweeds that have the whitish funnel-form corolla of the morning glory. The two most common are in the genus Calystegia and are are different from our species by having cup-like bracts at the base of the calyx. They are Hedge Bindweed, Calystegia sepium, which has a much larger flower and Low Bindweed, Calystegia spithamaea, which has a similar size flower but leaves that are oblong to ovate.
Above: Flowers and dark green leaves of Field Bindweed. Illustration courtesy Kurt Stüber's Online Library
Below: 1st photo - Corolla lobes are frequently tinged with pink along the edges of each lobe. 2nd photo - note the greenish-red lobes of the calyx are not hidden by cup shaped bracts.
Below: A comparison of Hedge Bindweed, Calystegia sepium, (on the left in both photos) and Field Bindweed. (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 but instead exposes the 5 green sepals. Note also the small bract on the stem below the calyx.
Below: Leaves usually have 2 descending lobes at the base and form an arrowhead shape. New leaves on new stem growth (2nd photo) frequently have fine hair as shown here
Notes: Field Bindweed is not indigenous to the Garden but was introduced by Eloise Butler on June 27, 1931 when she got some plants from 6th Ave. N & 6th St, from platform of Great Northern bus barn. Field Bindweed was present during Martha Crone's tenure as curator and was listed on her 1951 census. She first planted it in August 1946. Field Bindweed is an import from Europe, found there in the wild from western Europe to China. In North America it covers the continent except the very far north. In Minnesota it is not found throughout the state, but mostly in counties of the southern half. The University Herbarium reports that the first specimen collected in Minnesota was in 1902 in Jackson County.
Additional notes on habit: Mrs. Grieve (Ref. #7) has interesting details on pollination: The flower has a design to insure cross pollination. The nectar is contained in 5 small sacs situated at the base of the filaments of the 5 stamens. An insect has to reach deep into the corolla to obtain the nectar and in so doing, knock pollen off the anthers and then will carry that pollen to the next plant. She notes however, that most flowers never set seed although the nectar and its fragrant aroma attract many insects. The root system, however insures that the plant will spread, pollination or no pollination.
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"