While no information is available regarding the direct effects of fire on field
bindweed plants and seeds, some information on the effects of various heat
treatments on viability of field bindweed seed is available.
Harmon and Keim [57] tested the longevity of several weed
seeds after burial in horse and cow manure over a period of 1 to 4 months. The
temperature in the horse and cow manure reached 158
°F (66 °C) and 150
°F (70 °C),
respectively, in 2 weeks. Percent germination of field bindweed seed before
burial was 84%. In horse manure, germination was 6% after 1 month (without acid
treatment), 8% after 2 months (with acid treatment), and 0% thereafter. In cow
manure, germination was 4% after 1 month (without acid treatment), 22% after 2
months (with acid treatment), 1% after 3 months (1 weak bindweed seedling was
obtained), and 0% thereafter. Field bindweed seeds retained viability longer
than all other weed seeds tested.
Similarly, most weed seeds tested by Wiese and others [148] were
killed after 3 days or more exposure at
120 °F (49 °C) in compost; it required 7 days of
exposure at 180 °F (83 °C) to kill
all field bindweed seed in compost. In dry air, all species survived 140
°F (60 °C) for 30
days. All seeds except field bindweed were killed in dry air by 160
°F (72 °C) for 3 days,
while it took 7 days of exposure at 180 °F (83
°C) to reduce viability of field bindweed seed from
about 30% to 7%, and 30 days to reduce field bindweed seed viability to 5%.
Field bindweed seed was
killed by a 12-day exposure in an outside storage
pile of compost. Ensiling field bindweed seed seemed to have no effect on its viability [156].
These results suggest that field bindweed seed may survive low severity fire.
The following description of field bindweed is based on descriptions found in several florae
[30,64,65,71,81,88,127]. It provides
characteristics that may be relevant to fire ecology, and is not meant for
identification. Keys for identification are available (e.g. [60,64,65,88,146,149]). Proper identification is
important if control strategies are planned, as
field bindweed may closely resemble some native morning-glories.
Field bindweed is a perennial vine arising from deep, persistent, spreading roots. It has slender, trailing to
somewhat twining, branched
stems, 8 to 79 inches (20-200 cm) long, sometimes forming tangled mats. Herbage is glabrous to
pubescent and leaves are variable, 0.4 to 4 inches (1-10 cm) long and 0.1 to 2.4
inches (0.3-6 cm) wide, with
petioles 5-40 mm long. Peduncles arise from leaf axils, range from 0.2 to 2.4
inches (0.5-6 cm)
long, and bear 1 to several flowers. Corollas are broadly funnelform, 0.6 to 1.2
inches (1.5-3 cm)
long and 0.9 to 1.4 inches (2.2-3.5 cm) broad. Fruit is a capsule, 5-10 mm long, bearing 1 to 4
seeds, each about 3-4 mm long. Kennedy and Crafts [74] provide a detailed description
of the anatomy of field bindweed.
Several authors describe variations in botanical characteristics of field
bindweed. A review by Weaver and Riley [144] indicates the leaves of field
bindweed vary greatly in size and shape with environmental factors such as light intensity,
soil moisture, and damage due to frequent cultivation or defoliation. Degennaro
and Weller [35] identified and characterized 5 biotypes among field bindweed
clones collected from a field in Indiana. Consistent variations in leaf
morphology, floral characteristics, flowering capacity, phenology, vegetative
reproduction potential, and accumulation of shoot and root biomass were found
between biotypes when grown in a controlled environment. Pollination studies
showed that presumed biotypes were self-incompatible. The variability in growth
and reproduction observed in field bindweed biotypes may explain the survival
and adaptability of a field bindweed population as environmental conditions and
control practices change.
Several researchers have described the anatomy and development of field
bindweed roots (e.g. [34,47,74,75]). The root system is characterized by a taproot with large numbers of
annual lateral roots that develop adventitiously throughout its length, and penetrate
the soil in all directions
(see Seedling establishment/growth for more detail).
Some laterals are ephemeral and some are persistent. It is by
these lateral roots that plants spread horizontally. Shoot buds arise on these
horizontal laterals and develop into rhizomes which, reaching the surface,
establish new crowns [47,74]. The ability to
produce buds, together with the root food reserves, favors vegetative
reproduction and makes field bindweed plants persistent [74]
(see Asexual regeneration for more detail).
Field bindweed taproots may be 2 to 10 feet (0.5-3 m) or more long. Other
vertical roots may penetrate to depths of 17 to 30 feet (5-9 m) [10,66,75],
depending on climate and soil type. Lateral roots are found primarily in the top
12 inches (30 cm) of soil, and most commonly in the upper 4 to 6 inches
[47,75,128]. In field bindweed plants grown from root cuttings in a sandy loam
soil in Oxford, England 70% of lateral root spread was in the top 3 to 6 inches
(7.5-15 cm) of soil, and none was below 12 inches (30 cm) [34]. Similarly, Swan
[128] notes that the lateral roots are generally found within the top 12 inches
(30 cm) of soil, but approximately 1 third of the total root system is in the vertical roots
below the 24 inch (60 cm) zone. Estimates of the amount of root by weight in the upper
24 inches (60 cm) of soil range
from 50% to 70% [133,144]. The concentration of food
reserves increases with root depth, and maximum percentages of reserves were
found in roots 6 to 8 feet (2-2.4 m) deep [10].
Field bindweed from an old-field site in Ontario was among the few plant
species observed in the laboratory that were not infected with native arbuscular
mycorrhizal fungi [76]. Field bindweed plants growing on disturbed sites in Utah were infected
with vesicular-arbuscular mycorrhizae [102].
Root exudations may decrease the germination of some crop seed (Grummer 1957, as cited by [128]).
Field bindweed is native to Europe and Asia. Field bindweed is successful in many types of
climates, including temperate, tropical, and mediterranean, but is most
troublesome for agriculture throughout the temperate zone, from 60°N
to 45°S latitude. Fifty-four countries report
field bindweed as a weed in 32 different crops [66].
Field bindweed most likely arrived in the
U.S. as contaminant in farm and garden seeds. Some
plants were introduced intentionally and planted ornamentally as ground cover or
in hanging baskets. It was first noted in Virginia in 1739 and was found all
along the eastern seaboard, from Virginia to Maine, by the early 1800s. Western
migration of field bindweed may have been hastened by the building of railroads; however,
field bindweed seeds
continued to arrive whenever immigrants settled new areas or whenever crop seed
was imported. A "bindweed plague" in the Great Plains in 1877 was attributed to Ukrainian settlers who
inadvertently brought the weed seed in wheat (Triticum spp.) seed during
the early 1870s. Field bindweed reputedly established in the Pacific Northwest when an
Oregon settler used it as a cover crop in his orchard. Field bindweed was evidently present
in California as early as 1838. By the end of the 1st quarter of the 20th
century, field bindweed was considered the "worst weed" in several states and a "serious
pest" in several others, especially west of the Mississippi ([95] and references therein).
The current North American distribution of field bindweed extends from the agricultural
regions of all provinces in Canada (except Newfoundland and Prince Edward
Island) southward throughout the United States and into northern Mexico. It is common to abundant
in the U.S., except in the extreme Southeast and parts of southern Texas, New Mexico, and
Arizona ([144] and references therein). Field bindweed is adventitious in Hawaii [121]. Plants database
provides a state distribution map of field bindweed. Field bindweed is
especially common in cultivated fields and gardens [30,37,50,54,58,60,64,72,81,88,106,110,141,146,149], along roadsides [30,37,50,54,72,81,110,127,141,146,149], railroads [141,146],
"disturbed sites" [37,96,151,153], and "waste places" [50,106,127,141,146]. It is
reported from ballast heaps in Nova Scotia [110].
A survey of weed specialists and herbaria in the continental U.S., conducted
in 1994 and 1995, found that field bindweed occurs at "serious" densities (> 1,000 acres/county) in 957
counties, "moderate" densities (250-1000 acres/county) in 845 counties; and
"low" densities
(< 250 acres/county) in 573 counties, in 47 of the 48 contiguous states.
Only Florida and the southern parts of states from South Carolina to Texas did
not report its presence. The authors also report that field bindweed infestations have increased
in several western states since 1970, but have decreased in importance in most Great Plains states [18].
The following lists suggest ecosystems and vegetation types in which field
bindweed may be invasive, especially following disturbance. It is unclear from
the literature which vegetation types may be susceptible to invasion by field
bindweed in the absence of disturbance. These lists were derived from known or perceived
ecological tolerances of field bindweed, are largely speculative, and may not be
exhaustive.
Fire as a control agent:
Prescribed fire alone is not likely to control field bindweed,
but it may be useful in combination with other methods (Callihan and others
1990, as cited by [86]). The effectiveness of prescribed fire as a control
method for field bindweed may vary with the invaded plant community and interactions with
other types of disturbance.
In C4-dominated grasslands, for example, long-term annually burned
watersheds had lower cover of nonnative species (including field bindweed) than unburned watersheds,
and fire reduced nonnative species richness by 80% to 90% [119]. Langstroth [82] recorded the
presence of field bindweed on experimental plots in a California grassland that were grazed by
domestic sheep (short duration) in the summer, but unburned. All other plots
(ungrazed/unburned, spring grazed/unburned, and all burning treatments) had no
field bindweed present.
It is unclear from these results how fire and grazing affect field bindweed
populations over the long term.
Postfire colonization potential:
Field bindweed has the potential to invade an area following fire. Fire provides a suitable seedbed
for field bindweed [42] by removing shade and exposing mineral soil.
Therefore, if field bindweed is present on or near the site prior to burning, there is
potential for its establishment and spread. It is a good idea to survey the
surrounding area for field bindweed and control plants that may contain seed that could be dispersed
into the burn.
Preventing postfire establishment and spread: The USDA Forest
Service's "Guide to Noxious Weed Prevention Practices" [137] provides
several fire management considerations for weed prevention in general that apply
to field bindweed.
Preventing invasive plants from establishing in weed-free burned areas is the
most effective and least costly management method. This can be accomplished
through careful monitoring, early detection and eradication, and limiting
invasive plant seed dispersal into burned areas by [51,137]:
re-establishing vegetation on bare ground as soon as possible
using only certified weed-free seed mixes when revegetation is necessary
cleaning equipment and vehicles prior to entering burned areas
regulating or preventing human and livestock entry into burned areas until
desirable site vegetation has recovered sufficiently to resist invasion by
undesirable vegetation
detecting weeds early and eradicating before vegetative spread and/or seed
dispersal
eradicating small patches and containing or controlling large infestations
within or adjacent to the burned area
In general, early detection is critical for preventing establishment of large
populations of invasive plants. Monitoring in spring, summer, and fall is
imperative. Managers should eradicate established field bindweed plants and
small patches adjacent to burned areas to prevent or limit seed dispersal into
the site [51,137].
The need for revegetation after fire can be based on the degree of desirable
vegetation displaced by invasive plants prior to burning and on postfire
survival of desirable vegetation. Revegetation necessity can also be related to
invasive plant survival as viable seeds, root crowns, or rhizomes capable of
reproduction. In general, postfire revegetation should be considered when
desirable vegetation cover is less than about 30% [51].
When prefire cover of field bindweed is absent to low, and prefire cover
of desirable vegetation is high, revegetation is probably not necessary after
low- and medium-severity burns. After a high-severity burn on a site in this
condition, revegetation may be necessary (depending on postfire survival of
desirable species), and intensive monitoring for invasive plant establishment is
necessary to detect and eradicate newly established invasives before they spread
[51].
When prefire cover of field bindweed is moderate (20-79%) to high
(80-100%), revegetation may be necessary after fire of any severity if cover of
desired vegetation is less than about 30%. Intensive weed management is also
recommended, especially after fires of moderate to high severity [51].
Fall dormant broadcast seeding into ash will cover and retain seeds. If there
is insufficient ash, seedbed preparation may be necessary. A seed mix should
contain quick-establishing grasses and forbs (exclude forbs if broadleaf
herbicides are anticipated) that can effectively occupy available niches.
Managers can enhance the success of revegetation (natural or artificial) by
excluding livestock until vegetation is well established (at least 2 growing
seasons) [51]. See Integrated Noxious Weed Management after Wildfires
for more information.
Field bindweed is primarily an agricultural weed, and occurs in cultivated
fields and other disturbed sites such as pastures, gardens, lawns, and along
roadsides and railways. Natural area managers are most likely to find it in
moist locations (e.g. riparian corridors and irrigated areas) on tracts once
used for agriculture [86].
Field bindweed was among several nonnative
plant species identified in a tallgrass prairie study in Kansas, where
nonnative species were most common at the town site and along human and
livestock travel corridors. A gradient was observed with a high abundance of
nonnative species in town to low abundance in prairie sites, with the
distribution of native plants forming a reverse gradient. Sources of nonnative plant introduction were related
to early cattle trails through the community, railroad and stockyard locations,
gardens, cultivated fields, livestock and wildlife activity. Nonnative plants
occurred on truck trails
into the upland prairie but had not yet invaded the surrounding grassland [40]. On study sites on open annual grassland and
blue oak savannah in California, field bindweed was found on both serpentine
and nonserpentine soil types.
It was most frequent near roads on nonserpentine soils and its frequency of occurrence decreased with
increasing distance from the road. This pattern was not observed on serpentine
soils [68].
Elevation range: Field bindweed has reportedly been found in
the Himalayas at altitudes of 10,000 feet (3,000 m) ([95] and references therein).
Field bindweed is found in several plant communities in riparian corridors in Wyoming, at
7,000 to 7,500 feet (2,100-2,300 m). Elevation ranges are given by area as follows:
Field bindweed is invasive primarily in agricultural areas, although some
authors indicate that it is also invasive in natural areas (e.g. [28,86,109]). Natural area managers are most
likely to find it in moist locations (e.g. riparian corridors and irrigated
areas) on tracts once used for agriculture [86]. Field bindweed is normally found in
open communities in association with annual, biennial, and short-lived perennial
weeds [144]. Habitats that are most like agricultural
lands (little competition, repeated disturbance, and high light intensity) are ideal for
growth of field bindweed (Cox (1915) as cited by [86]).
California: Field bindweed establishes locally in vernal pools in
Sacramento County, and in large pools in Tehama County. These habitats support populations of endangered hairy Orcutt
grass (Orcuttia pilosa) and Hoover's spurge (Chamaesyce hooveri),
and also support thriving field bindweed and cocklebur (Xanthium strumarium var. canadense) populations. Field bindweed occurs in open
annual grassland and oak savannah sites. Dominant natives include blue oak (Quercus douglasii) and chamise (Adenostoma
fasciculatum). Grassland natives include purple needlegrass (Nassella pulchra),
Sandberg bluegrass (Poa secunda),
California melic grass (Melica californica), small fescue (Vulpia microstachys),
and many native forbs [68]. At Sugarloaf Ridge
State Park, field bindweed is occasional in disturbed
places such as campgrounds and horse corrals [19].
In Nevada, field bindweed occurs on disturbed, moist soil of cultivated fields, near springs, roadsides, and
homesteads with pinyon (Pinus spp.), juniper (Juniperus spp.), and
saltbush (Atriplex spp.) [71].
At the Thousand Springs Preserve, Idaho, field bindweed thrives under
cultivated and irrigated conditions, and managers there suggest that field
bindweed outcompetes native grasses [86,109]. At Garden Creek Preserve in northern Idaho, managers report that
field bindweed threatens bunchgrass and forb-dominated habitats [86].
In Colorado, field bindweed has been identified in "seemingly remote, undisturbed
aspen stands" in Rocky Mountain National Park [28]. At the Phantom
Canyon Preserve, field bindweed is most problematic in
riparian corridors and mountain-mahogany (Cercocarpus spp.) shrubland/grassland [86].
Midwest: Field bindweed occurs with purple loosestrife (Lythrum salicaria) in wetland sites in the
Midwest [132]. It occurs in Theodore Roosevelt National Park in North Dakota [26], and occurs in the understory in
eastern cottonwood (Populus deltoides) stands along the Missouri River in southeastern South Dakota [150].
Field bindweed had relatively high (compared with other regulated noxious weeds)
frequency and canopy cover on study areas in the glaciated prairie pothole
region of the Northern Great Plains [61].
Canada: Field bindweed is a dominant species in some disturbed riverbank areas in the Montréal
area of Québec. Codominant species include
common wormwood (Artemisia vulgaris), common dandelion (Taraxacum officinale), and
bird vetch (Vicia cracca) [97].
Dioscorides (circa A.D. 50) recommended drinking tea made from field bindweed
seeds for 40 days to cure spleen problems, weariness, and hiccups. However, he
warned, it had the inconvenient side effects of causing one to urinate blood
after the 6th day and making one permanently sterile after the 37th (as cited by
[95]). According to Kearney and others [72], an antihemorrhagic substance has been discovered in
field bindweed, although the source of this information is not given.
Extracts from field bindweed leaves and stems show high larvacidal activity against mosquito larvae [20].
There is no information available regarding field bindweed response to fire.
Field bindweed probably sprouts from roots and rhizomes if top-killed by fire. Response of field bindweed populations to
fire depends on a number of factors, including
native and imposed FIRE REGIMES, site conditions (e.g. soil, moisture,
temperature), associated plant communities, management history, and disturbance
regimes at a particular site.
In a study on the effects of litter on
germination and establishment of cheatgrass and medusahead, field bindweed germinated and grew well without litter,
suggesting that field bindweed may do well in a
postfire environment. When litter was present, and with increased competition from grasses, yields of
field bindweed were
"drastically curtailed" [42].
Field bindweed tends to be an early successional species, as it establishes well on bare
ground under open conditions. Disturbed sites are common habitat for field
bindweed
throughout its range (e.g. [37,50,96,106,127,141,146,151,153]). On a site in
western Nevada, field bindweed germinated and established better on microsites with bare
ground than on microsites with litter, and occupied
early successional stages (mostly grazing disturbance) in
some rangeland plant communities [42].
It is unclear how long field bindweed plants may persist in native plant communities.
Field bindweed plants were still present in an abandoned farm field 30 years after it was
last farmed in tallgrass mixed hardwood forest in Minnesota [59].
A review by Holm and others [66] suggests
that competition for sunlight places field bindweed at a disadvantage, and that, if adequate soil moisture is present,
several crop plants will force
it into abnormal growth and dormancy by shading. When crop plants are removed,
field bindweed resumes active growth [66]. Similarly, on a site in western
Nevada, scattered plants of field bindweed were observed growing intermixed with, but suppressed by a
medusahead (Taeniatherum caput-medusae) population. When medusahead was reduced by a variety of methods
(herbicide, disk-harrow, furrow), medusahead reduction was
followed by heavy infestations of field bindweed [155].
Bakke (1939, as cited by [9]) reports that shaded
field bindweed plants lose their prostrate habit and become twining plants. In general, the
lower the light intensity reaching field bindweed plants, the more rapid the elimination of
above- and belowground parts and the more reduction of available root
carbohydrates [9]. Dall'Armellina and Zimdahl [32] found that flower production, leaf area, and dry matter of shoots,
roots, and rhizomes
of field bindweed grown from seed declined as light level decreased. The only response
to reduced light levels of plants grown from rhizome segments was complete inhibition of rhizome
production [32]. A study by Mashhadi
and others [89] characterized the photosynthetic rate of
field bindweed under varied
light levels, measured as photosynthetic photon flux
(PPF). Field bindweed showed a linear response to PPF levels. Photosynthesis and transpiration both decreased at the
same rate in response to
decreasing PPF. There was a small amount of transpiration in darkness. The
authors also noted that field bindweed
growing under a dense juniper canopy had mostly abscised or chlorotic lower
leaves and long internodes on stems far from sunlight. They speculated that
field bindweed plants were able to establish in this low light environment
either because the leaves had adapted to low light and/or root reserves were
used to support the initial growth stages.
The competitive ability of field bindweed is due largely to its extensive root system. One
plant is able to reduce the available soil moisture in the top 24 inches (60 cm) of soil
below the "wilting point" (Wiese, unpublished data in [144]). Bakke [8] characterized the competitive
interaction between corn and field bindweed in Iowa,
noting that field bindweed is a superior competitor for water under conditions of low soil
moisture, and that corn plants growing with field bindweed were smaller and had lower
yields. How the competitive ability of field bindweed might affect successional trajectories
native plant communities is unknown.
Convolvulus arvensis, the field bindweed, is a species of bindweed that is rhizomatous and is in the morning glory family (Convolvulaceae),[1] native to Europe and Asia. It is a climbing or creeping herbaceous perennial plant with stems growing to 0.5–2 metres (1.6–6.6 ft) in length, 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.
This plant first gained its scientific name in 1753, when it was described by Linnaeus in the Species Plantarum. In the centuries afterwards it gained many subspecies and varieties across its vast range, as well as synonyms as purportedly new species were described from places like China, Russia, Egypt or Morocco. New species and forms were even described from areas like Chile, Mexico and California when botanists encountered the plant there,[2][3] although it is not native to these areas.[2]
In the ninth volume of Augustin Pyramus de Candolle's Prodromus, published in 1845, Jacques Denys Choisy reduced a number of these synonyms to ten varieties of Convolvulus arvensis,[4] although he also recognised a number of species now also reduced to synonyms of C. arvensis.[2][3] Over time, most or all of these species and varieties were no longer recognised by the relevant authorities.[5]
In the 2009 Flora of Great Britain and Ireland, Peter Derek Sell described nine new forms he believed he had discovered in Cambridgeshire, especially along Fen Road in the village of Bassingbourn cum Kneesworth. The incredible bindweed biodiversity of Bassingbourn cum Kneesworth was not deemed credible by subsequent taxonomists, however, and the species is currently considered to be monotypic by most authorities.[2][3]
Convolvulus arvensis is a perennial vine. It will climb to some one metre high. Underground the vine produces more or less woody rhizomes,[5] from which it re-sprouts in the spring, or when the above ground vines are removed.
The leaves are spirally arranged, linear to arrowhead-shaped, 2–5 cm (0.79–1.97 in) long and alternate, with a 1–3 cm (0.39–1.18 in) petiole. The flowers are trumpet-shaped, 1–2.5 cm (0.39–0.98 in) diameter, white or pale pink, with five slightly darker pink radial stripes. Flowering occurs in the mid-summer,[6] (in the UK, between June and September,[7]) 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 0.125 inches (3.2 mm) 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.[6]
Convolvulus arvensis can be confused with a number of similar weed species. Key traits are the small flowers often crowded together, and two sharp, backwards-pointed lobes at the base of the usually arrow-shaped leaf ending in a sharp apex.[8] Juvenile stems exude a milky sap when broken.[9]
In China, the most similar and only other vinaceous Convolvulus species is C. steppicola (most of the Convolvulus species are shrubs or herbaceous perennials),[10] however this species has a thick woody rootstock, almost no petioles, and only grows in northern Yunnan,[10][11] where C. arvensis is absent.[5]
Plants are typically found inhabiting farmland,[5][7][12] waste places,[5][7][13] along roads,[5][12][13] in pastures,[12][13] grassy slopes,[5] and also along streams in North America.[12] It is able to colonise hot asphalt surface by covering it from the sides of roads, and worm its way between pavement stones.[7] It grows from 600 to 4,500 metres (2,000 to 14,800 ft) in altitude in China, and is absent from the warmer southern provinces.[5] It prefers dry areas with humus-poor, nutrient-rich and alkaline soils. It is a characteristic species in the phytosociological vegetation association Convolvulo-Agropyretum, belonging to the couch grass dry grasslands alliance (called Convolvulo-Agropyrion repentis in syntaxonomy).[13]
Like the other Convolvulus bindweeds of Eurasia, it is specifically pollinated by sweat bees in the genus Systropha. These are specialists (oligolectic) feeding upon the flowers of these plants, possessing unusual modifications of the scopa, such that almost the entire abdomen (including the dorsal surface) is used for carrying pollen, rather than the legs, as in most bees.[14] 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,[15] 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.[16] These species are themselves specifically parasitised upon by the cuckoo bee Biastes brevicornis.[17]
Outside its native range, field bindweed does not appear to be a significant threat to natural habitats. It primarily requires disturbed ground (agricultural land),[18][19] and is easily shaded out by taller shrubs and trees. It may dominate the ground flora in some low quality, open grassland areas, however.[18] In North America it can become the or a co-dominant plant in specific habitats: the low vegetation found around vernal pools in Sacramento County, and around large pools in Tehama County, California; riparian corridors in Wyoming and Colorado; aspen stands and mountain-mahogany (Cercocarpus spp.) shrubland/grassland in Colorado; and disturbed riverbank areas in the Montreal area of Canada.[19] In some nature parks, it is commonly found in areas of disturbed soil, such as camp grounds or around horse corrals in California. Similarly, the report of its invasive character from Colorado is from former agricultural land being restored to a more natural state by The Nature Conservancy. Employees for the same organisation also reported that it was a significant weed on an irrigated plot of farmland in northern Idaho where native bunchgrass and forbs were cultivated, insofar that it caused "decreasing biodiversity" on the land.[19]
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.[18][19] and the alkaloids it contains may be poisonous to horses in sufficient amounts.[20] There are also reports of it being eaten by sheep and pigs to control it without reported problems.[19]
Bindweed contains several alkaloids which are toxic for mice, including pseudotropine, and lesser amounts of tropine, tropinone, and meso-cuscohygrine.[21]
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.[12] It is one of the most serious weeds of agricultural fields in many temperate regions of the US.[22]
Bindweed is difficult to eliminate. Roots may extend as far as 9 feet (2.7 m) deep, according to one source,[9] or 30 feet (9.1 m), according to another.[23] New plants may sprout from seeds that are up to 20 years old.[24] New plants can also form from root runners[23] and root fragments.[9]
Methods for controlling bindweed include:
In one of the tales collected by Jacob and Wilhelm Grimm, Our Lady's Little Glass, this flower is used by Mary, mother of Jesus, to drink wine with when she helps free a wagoner's cart. The story goes on to say that "the little flower is still always called Our Lady's Little Glass".[27]
Convolvulus arvensis, the field bindweed, is a species of bindweed that is rhizomatous and is in the morning glory family (Convolvulaceae), native to Europe and Asia. It is a climbing or creeping herbaceous perennial plant with stems growing to 0.5–2 metres (1.6–6.6 ft) in length, 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.
