Convolvulus arvensis

Species of bindweed

Convolvulus arvensis, or field bindweed, is a species of bindweed in the Convolvulaceae native to Europe and Asia. It is a rhizomatous and climbing or creeping herbaceous perennial plant with stems growing to in length. It is usually found at ground level with small white and pink flowers. Other common names, mostly obsolete, include lesser bindweed, European bindweed, withy wind (in basket willow crops), perennial morning glory, small flowered morning glory, creeping jenny, and possession vine.

Field bindweed was first described in 1753 by Carl Linnaeus in the Species Plantarum. In the following centuries, many subspecies, varieties, and synonymous taxa were discovered and described as purportedly new species in places including China, Russia, Egypt, and Morocco. New species and forms were described as far as Chile, Mexico, and the state of California when botanists encountered the plant there, although it is not native to these areas. although he also recognized a number of species now also reduced to synonyms of C. arvensis. In the Flora of Great Britain and Ireland (2009), Peter Derek Sell described nine new forms he believed he had discovered in Cambridgeshire, along Fen Road in the village of Bassingbourn cum Kneesworth. The forms discovered in Bassingbourn cum Kneesworth were deemed not credible by subsequent taxonomic authorities, however, and the species is currently considered to be monotypic by most authorities. (in the UK, between June and September) when white to pale pink, funnel shaped flowers develop. Flowers are approximately 0.75–1 in (1.9–2.5 cm) across and are subtended by small bracts. Fruit are light brown, rounded and wide. Each fruit contains 2 or 4 seeds that are eaten by birds and can remain viable in the soil for decades. The stems climb by twisting around other plant stems in a counter clockwise direction. Juvenile stems exude a milky sap when broken. Similar species include:
Calystegia sepium Large white flowers. Squarish however Convolvulus steppicola has a thick woody rootstock, almost no petioles, and only grows in northern Yunnan, where C. arvensis is absent. waste places, along roads, Species of Systropha in central Europe (such as S. curvicornis and S. planidens, both uncommon bees) are essentially entirely dependent upon C. arvensis. Although both species specialise on the same plant species, S. curvicornis is a habitat generalist while S. planidens is only found in steppe habitats, although they are also found occurring together. The males of both species claim territories consisting of a patch of bindweed flowers, perching on the flowers in the afternoon after a regular patrol of their little patch for errant conspecific males, which, upon countenance, they proceed to attack the intruder by ramming him from the air with a specialised protuberance on their lower abdomen. Sometimes bumblebees, honey bees or other insects are air bombed, but never rammed. The males retreat inside the flower after the perching session, as it closes in the late afternoon, spending the night inside the flower and escaping at dawn before or after it fully closes (the females stay in underground tunnel nests). The males only land on flowers (sometimes of other plants), eschewing other perches, and feed on the nectar. Females forage for nectar and pollen in the morning and early afternoon while flowers stay open. Most copulation occurs in bindweed flowers: when a virgin female wanders into their patch, and the larger males find them busy at one of their flowers during morning patrol, the males pounce upon them without ado and immediately establish contact with their mutual genitalia, getting the job done on average 90 seconds later. These species are themselves specifically parasitised upon by the cuckoo bee Biastes brevicornis.

Outside its native range, field bindweed does not appear to be a significant threat to natural habitats. It primarily requires disturbed ground (agricultural land), and is easily shaded out by taller shrubs and trees. It may dominate the ground flora in some low quality, open grassland areas, however. It is thought to have little effect on native fauna, although it may sometime be eaten by farm livestock. It may cause photosensitisation in susceptible animals. There is a report of its roots (rhizomes) being possibly poisonous to pigs. There are also reports of it being eaten by sheep and pigs to control it without reported problems. The alkaloids are also reported to give the plant psychoactive properties. Its leaves contain glycosides and have been traditionally used to treat hypertension and as a laxative and diuretic.

Although it produces attractive flowers, it is often unwelcome in gardens as a nuisance weed due to its rapid growth and choking of cultivated plants. It was most likely introduced into North America as a contaminant in crop seed as early as 1739, and became an invasive species. Its dense mats invade agricultural fields and reduce crop yields; it is estimated that crop losses due to this plant in the United States exceeded US$377 million in the year 1998 alone.

Bindweed is difficult to eliminate. Roots may extend as far as 9 feet (3 m) deep, according to one source, New plants may sprout from seeds that are up to 20 years old. New plants can also form from root runners
Biological control: Some insects and mites can eat, distort or stunt bindweed, but do not fully control it. Grazing: In Minnesota, sheep are able to consistently completely rid an infested pasture of the bindweed in two seasons, but only when the pasture is used to grow annual grains.