Asclepias syriaca | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Gentianales |
Family: | Apocynaceae |
Genus: | Asclepias |
Species: | A. syriaca |
Binomial name | |
Asclepias syriaca | |
Asclepias syriaca, commonly called common milkweed, butterfly flower, silkweed, silky swallow-wort, and Virginia silkweed, is a species of flowering plant. [2] [3] It is native to southern Canada and much of the United States east of the Rocky Mountains, excluding the drier parts of the prairies. [4] It is in the genus Asclepias , the milkweeds. It grows in sandy soils as well as other kinds of soils in sunny areas.
A. syriaca is a clonal perennial forb growing up to 1.8 m (5 ft 11 in) tall. [5] Individual plants grow from propagative roots. [6] All parts of common milkweed plants produce a white latex when cut. The simple leaves are opposite, sometimes whorled; broadly ovate-lanceolate. They grow to 10–28 cm (4–11 in) long and 4–12 cm (1+1⁄2–4+3⁄4 in) broad, [5] usually with entire, undulate margins and reddish main veins. They have very short petioles and velvety undersides.
The highly fragrant, nectariferous flowers vary from white (rarely) through pinkish and purplish and occur in umbellate cymes. [7] Individual flowers are about 1 cm (0.4 in) in diameter, each with five horn-like hoods and five pollinia. The seeds, each with long, white flossy hairs, occur in large follicles. Fruit production from self-fertilization is rare. In three study plots, outcrossed flowers had an average of about 11% fruit set. [8]
More than 450 insect species feed on A. syriaca, including flies, beetles, ants, bees, wasps, and butterflies. It is among the most important food sources for monarch butterfly (Danaus plexippus) caterpillars in the northeastern and midwestern United States and is one of only three milkweed species on which the eastern monarch migration largely depends. Other insects that feed on the plant include the red milkweed beetle (Tetraopes tetraophthalmus), the milkweed tussock caterpillar (Euchaetes egle), the large milkweed bug (Oncopeltus fasciatus), and the small milkweed bug (Lygaeus kalmii). [3] [9]
Many kinds of insects visit A. syriaca flowers, and some kinds pollinate them, including Apis mellifera , the Western honey bee, and native Bombus spp. (bumblebees). [10] In the U.S. mid-Atlantic region, the introduced species A. mellifera was found to be the most "effective" pollinator, but this occurs more often among flowers of the same plant; since A. syriaca has a high level of self-incompatibility, it is less effective than Bombus spp. in the fertilization of flowers because Bombus are more likely to visit unrelated individuals. [11]
Monarch butterfly larvae consume primarily milkweeds, and monarch populations may decline when milkweeds are eliminated with herbicides. [12] The development and widely adopted cultivation of herbicide-resistant staple crops such as corn and soybeans have led to a massive reduction in weeds and native plants such as milkweeds. [13] Consequently, this has played a significant part in the population decline of the monarch butterfly. In 2018, the chief executive officer (CEO) of the National Wildlife Federation stated that the monarch butterfly population had decreased by 90 percent during the previous 20 years and cited the reduction in milkweed as a contributing factor. [14]
Many parts of the United States face a reduction in milkweed population due to factors such as increased habitat loss due to development, roadside median mowing, and herbicide use. [15] Despite this, deforestation due to human settlement may have expanded the range and density of common milkweed in some regions. [16] Common milkweed has even become invasive as it is naturalized in several areas outside of its original native range, including Oregon and some parts of Europe. Since 2017, common milkweed has been listed as an invasive species in the European Union, [17] making the import and trade of the species forbidden in the whole of the European Union. [18] It has been naturalized in 23 countries worldwide. [19]
Over 40 distinct pathogens of Asclepias species have been identified, including two dozen pathogens for A. syriaca. [20] For example, milkweed yellows is an infectious disease caused by the milkweed yellows phytoplasma, a strain of bacteria distinguished by the absence of a cell wall.
A. syriaca can become aggressive. [2] It spreads from propagative roots and may not be suited to small gardens and formalized plantings. [21] The plant is winter hardy in USDA zones 3–9; it has a preference for moist but well drained soils, but is tolerant of dry conditions and clay soils. [22] It is ideal in semi-dry places where it can spread without presenting problems for other ornamental species. [2]
Monarch Watch provides information on rearing monarchs and their host plants. [23] Efforts to restore falling monarch butterfly populations by establishing butterfly gardens and monarch migratory "waystations" require particular attention to the target species' food preferences and population cycles, as well to the conditions needed to propagate and maintain their food plants. [24]
In the northeastern United States, monarch reproduction peaks in late summer when most of the plant's leaves are old and tough. Plants that are mowed or cut back in June – August regrow rapidly from their roots in time for peak monarch egg-laying, when reproducing female monarchs have a preference for quickly-growing A. syriaca shoots whose foliage is tender and soft. [25]
A. syriaca can be grown from seeds and propagative root cuttings. [2] A U.S. Department of Agriculture conservation planting guide for Maryland recommends that, for optimum wildlife and pollinator habitat in mesic sites (especially for monarchs), a seed mix should contain 6.0% A. syriaca by weight and 2.0% by seed. [26] The plant's seeds require a period of cold treatment (cold stratification) before they will germinate. [27]
To protect seeds from washing away during heavy rains and from seed–eating birds, one can cover the seeds with a light fabric or with an 0.5 in (13 mm) layer of straw mulch. [28] However, mulch acts as an insulator. Thicker layers of mulch can prevent seeds from germinating if they prevent soil temperatures from rising enough when winter ends. Further, few seedlings can push through a thick layer of mulch. [29] Both seedlings and cuttings will usually bloom in their second year, although cuttings will occasionally bloom during their first year. [2]
The nonnative Aphis nerii (oleander aphid) can become abundant on milkweed shoots. [30]
The plant's latex contains large quantities of cardiac glycosides, making the leaves and stems of old tall plants toxic to humans and large animals. [31] The young shoots, young leaves, flower buds and immature fruits are all edible raw. [32]
Euell Gibbons, the author of Stalking the Wild Asparagus (1962), wrote that milkweed is bitter and toxic. However, he may have inadvertently prepared common dogbane ( Apocynum cannabinum ), a poisonous somewhat similar-looking plant instead. Gibbons devised a method to remove the bitterness and toxicity by plunging the young shoots into boiling water and cooking for one minute, repeating the procedure at least three times to make the plant safe to eat. Some modern foragers consider the bitterness and toxicity issue a myth. The plants have no bitterness when tasted raw, and can be cooked like asparagus, with no special processing. [32]
The plant has been studied as a source of rubber from the latex of the plant, [33] and as a fiber source from the seed fluff. The fluffy seed hairs have been used as the traditional background for mounted butterflies and other insects. The compressed floss has a silk-like sheen. The plant has also been explored for commercial use of its bast (inner bark) fiber, which is both strong and soft. U. S. Department of Agriculture studies in the 1890s and 1940s found that common milkweed has more potential for commercial processing than any other indigenous bast fiber plant, with estimated yields as high as hemp and quality as good as flax. Both the bast fiber and the floss were used historically by Native Americans for cordage and textiles. Milkweed has also been cultivated commercially to be used as insulation in winter coats. [34]
Traditionally, in both North America and Europe, the plant was used to treat respiratory infections such as pleurisy. [35]
The genome of A. syriaca has been sequenced. [16] Genomic analysis of several hundred different A. syriaca plants from throughout the species natural range in eastern North America showed that this species is a single panmictic population that experienced expansions about 12,000 years ago, after the recession of North American glaciers, and more recently, about 200 years ago, during clearing of forests for agriculture in the eastern United States. [16]
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: CS1 maint: multiple names: authors list (link)Examples of plants with modified roots: Common milkweed (Asclepias syriaca) and Canada thistle (Cirsium arvense).
Examples of plants with modified roots: Common milkweed (Asclepias syriaca) and Canada thistle (Cirsium arvense).
The local monarch favorite is Common Milkweed (A. syriaca), but this may not be the best for a formal setting since they spread by underground stolons and so will not "stay" where they are planted.
Could roadside mowing stimulate milkweed growth and support monarch breeding? Limited research in eastern North America has shown that spring or summer mowing can promote new growth and extend the availability of milkweed plants for monarch breeding. Mowing may stimulate growth of some milkweed species, particularly those that spread through rhizomes like common milkweed (A. syriaca) and showy milkweed (A. speciosa). .... However, more research is needed in other areas to determine the optimal timing and frequency of mowing that promotes not only milkweed but also nectar plants. It is also unknown if the benefit of additional milkweed availability in the fall outweighs the costs of the larval mortality caused by summer mowing. The benefits are likely greater in areas that primarily have breeding monarchs in the spring and fall and where the dominant species of milkweed spread by rhizomes. Sources: Alcock et al. 2016; Baum and Mueller, 2015; Bhowick 1994; Haan and Landis 2019; Fischer et al. 2015
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: CS1 maint: multiple names: authors list (link)"The monarch doesn't care where the milkweed grows, and putting it in residential neighborhoods makes perfect sense," said Doug Tallamy, an entomologist at the University of Delaware, author and expert on wildlife habitat gardens. ....
The Smithsonian Institution's Butterfly Habitat Garden .... and the Ripley Garden .... are both good places to see milkweed integrated into a garden setting.
At the butterfly garden, you can see the common milkweed ... now looking pretty good in fresh, unblemished clumps. By late summer, it looks tall, tired and tough. Tallamy says if you grow it, you should cut it back at least by half in June to produce soft foliage in late summer that will be more munchable for the caterpillars. If you do that, make sure there are no larvae on the plant before you chop it.
Virginia is blessed for instance with 13 native Asclepias species plus 4 climbing vines that Monarch caterpillars can feed on. For the best results, cut some of the stems back in late summer after they've bloomed. Fall is the when we get the most Monarchs laying eggs on our milkweeds. Since the mother butterflies prefer young, more tender growth, you can provide this by timing your pruning so there are new leaves by September or so for the arriving Monarchs. Just make sure to leave a few to produce pods for seeds. The local monarch favorite is Common Milkweed (A. syriaca), .....
Cut- At mid season after the blooms have faded, cut some common plants back by about a third. This promotes fresh plant growth and could get you an extra generation of monarchs on the fresh new leaves. Leave some plants uncut if you want to harvest milkweed seeds in fall.
This mix has a predominant wildflower component for optimum wildlife and pollinator habitat.
Many sources of milkweed seeds require stratification (cold, moist treatment) before sowing. In a review of stratification requirements for common milkweed, recommendations varied from as short as 7 days to as long as 11 months at 5°C (41°F) (Luna and Dumroese, 2013)
Seed may be stubborn to germinate and may need a period of cold treatment.
Start seeds indoors 2 months before final frost- seeds must be cold stratified.
If planting in flats or in a greenhouse, common milkweed seeds should be cold-treated for three months.
germination: seed requires cold moist period.
Any of the standard seed propagation methods (Landis et al., 1999) are effective with milkweed. Direct sowing of non-stratified seeds during the fall followed by exposure to ambient winter conditions can be effective, but the seeds must be mulched and protected. Cover sown seeds with a thin mulch; research has found that common milkweed seeds germinate better when planted 1 to 2 cm (0.4 to 0.8 in.) deep than when at the soil surface (Jeffery and Robison, 1971).
Asclepias tuberosa, commonly known as butterfly weed, is a species of milkweed native to eastern and southwestern North America. It is commonly known as butterfly weed because of the butterflies that are attracted to the plant by its color and its copious production of nectar.
The monarch butterfly or simply monarch is a milkweed butterfly in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. It is among the most familiar of North American butterflies and an iconic pollinator, although it is not an especially effective pollinator of milkweeds. Its wings feature an easily recognizable black, orange, and white pattern, with a wingspan of 8.9–10.2 cm (3.5–4.0 in). A Müllerian mimic, the viceroy butterfly, is similar in color and pattern, but is markedly smaller and has an extra black stripe across each hindwing.
Asclepias is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans and many other species, primarily due to the presence of cardenolides. However, as with many such plants, some species feed upon milkweed leaves or the nectar from their flowers. A noteworthy feeder on milkweeds is the monarch butterfly, which uses and requires certain milkweeds as host plants for their larvae.
Asclepias incarnata, the swamp milkweed, rose milkweed, rose milkflower, swamp silkweed, or white Indian hemp, is a herbaceous perennial plant species native to North America. It grows in damp through wet soils and also is cultivated as a garden plant for its flowers, which attract butterflies and other pollinators with nectar. Like most other milkweeds, it has latex containing toxic chemicals, a characteristic that repels insects and other herbivorous animals.
Butterfly gardening is a way to create, improve, and maintain habitat for lepidopterans including butterflies, skippers, and moths. Butterflies have four distinct life stages—egg, larva, chrysalis, and adult. In order to support and sustain butterfly populations, an ideal butterfly garden contains habitat for each life stage.
Asclepias asperula, commonly called antelope horns milkweed or spider milkweed, is a species of milkweed native to the Southwestern United States and northern Mexico.
Asclepias curassavica, commonly known as tropical milkweed, is a flowering plant species of the milkweed genus, Asclepias. It is native to the American tropics and has a pantropical distribution as an introduced species. Other common names include bloodflower or blood flower, cotton bush, hierba de la cucaracha, Mexican butterfly weed, redhead, scarlet milkweed, and wild ipecacuanha.
Asclepias purpurascens, the purple milkweed, is a herbaceous plant species. It is in the genus Asclepias, making it a type of milkweed. It is native to the Eastern, Southern and Midwestern United States similar to the range of the common milkweed. The plant gets its name from the flowers that first develop a pink color but then turn darker purple as they mature. Unlike common milkweed, purple milkweed prefers some shade and is considered a plant of partial shade. It is also considered an indicator of oak savanna, especially in Wisconsin. The species rarely produces seed pods which are smooth, instead of the rough warty ones produced by common milkweed.
Asclepias verticillata, the whorled milkweed, eastern whorled milkweed, or horsetail milkweed, is a species of milkweed native to most of eastern North America and parts of western Canada and the United States.
Asclepias fascicularis is a species of milkweed known by the common names narrowleaf milkweed and Mexican whorled milkweed. It is a perennial herb that grows in a variety of habitats.
Asclepias californica is a species of milkweed known by the common name California milkweed. It grows throughout lower northern, central and southern California.
Asclepias speciosa is a milky-sapped perennial plant in the dogbane family (Apocynaceae), known commonly as the showy milkweed and is found in the western half of North America.
Asclepias meadii is a rare species of milkweed known by the common name Mead's milkweed. It is native to the American Midwest, where it was probably once quite widespread in the tallgrass prairie. Today much of the Midwest has been fragmented and claimed for agriculture, and the remaining prairie habitat is degraded.
Asclepias viridis is a species of milkweed, a plant in the dogbane family known by the common names green milkweed, green antelopehorn and spider milkweed. The Latin word viridis means green. The plant is native to the midwestern, south central and southeastern United States, as well as to the southeastern portion of the western United States.
Asclepias quadrifolia, commonly called four-leaved milkweed or fourleaf milkweed, is a species of milkweed in the Apocynaceae (dogbane) family. It is sometimes referred to as whorled milkweed, but it should not be confused with Asclepias verticillata. A. quadrifolia occurs in the eastern United States and Canada.
Asclepias lanceolata, the fewflower milkweed, is a species of milkweed that is native to the coastal plain of the United States from New Jersey to Florida and Southeast Texas. A. lanceolata is an upright, perennial plant that can grow between 3 and 5 feet tall, with red-orange flowers blooming in the summer months. It can also be referred to as Cedar Hill milkweed, as it was first described by Dr. Eli Ives in the neighborhood of Cedar Hill in New Haven, Connecticut.
Asclepias sullivantii is a species of flowering plant in the milkweed genus, Asclepias. Common names include prairie milkweed, Sullivant's milkweed, and smooth milkweed. It is native to North America, where it occurs in the central United States and Ontario in Canada.
Asclepias exaltata is a species of flowering plant in the dogbane family, native to eastern North America.
Asclepias angustifolia, commonly called the Arizona milkweed, is an endemic species of milkweed native only to Arizona.
A pollinator garden is a type of garden designed with the intent of growing specific nectar and pollen-producing plants, in a way that attracts pollinating insects known as pollinators. Pollinators aid in the production of one out of every three bites of food consumed by humans, and pollinator gardens are a way to offer support for these species. In order for a garden to be considered a pollinator garden, it should provide various nectar producing flowers, shelter or shelter-providing plants for pollinators, and avoid the use of pesticides.
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