Misplaced Pages

Apocynaceae

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
#237762

34-570: Apocynaceae ( / ə ˌ p ɑː s ə ˈ n eɪ s i ˌ aɪ , - s iː ˌ iː / , from Apocynum , Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family , because some taxa were used as dog poison. Members of the family are native to the European, Asian, African, Australian, and American tropics or subtropics, with some temperate members. The former family Asclepiadaceae (now known as Asclepiadoideae )

68-471: A DNA study indicate that, generally, more recently evolved milkweed species ("derived" in botany parlance) use these preventive strategies less but grow faster than older species, potentially regrowing faster than caterpillars can consume them. Research indicates that the very high cardenolide content of Asclepias linaria reduces the impact of the Ophryocystis elektroscirrha (OE) parasite on

102-438: A gynostegium surrounded by a five-membrane corona . The corona is composed of a five-paired hood-and-horn structure with the hood acting as a sheath for the inner horn. Glands holding pollinia are found between the hoods. The size, shape and color of the horns and hoods are often important identifying characteristics for species in the genus Asclepias . Pollination in this genus is accomplished in an unusual manner. Pollen

136-435: A synsepalous , five-lobed calyx united into a tube at the base. Inflorescences are terminal or axillary . Five petals are united into a tube with four or five epipetalous stamens . The style head is swollen. The pollen is transported in foam. The ovary is usually superior , bicarpellary, and apocarpous, with a common fused style and stigma. (Fig. 5. and Fig.6. in the illustration of Rhigospira quadrangularis show

170-766: A cluster of white, silky, filament-like hairs known as the coma (often referred to by other names such as pappus , "floss", "plume", or "silk"). The follicles ripen and split open, and the seeds, each carried by its coma, are blown by the wind . Some, but not all, milkweeds also reproduce by clonal (or vegetative) reproduction. There are also 12 species of Asclepias in South America, among them: A. barjoniifolia , A. boliviensis , A. curassavica , A. mellodora , A. candida , A. flava , and A. pilgeriana . Milkweeds are an important nectar source for native bees , wasps , and other nectar-seeking insects, though non-native honey bees commonly get trapped in

204-541: A food source for monarch butterfly larvae and some other milkweed butterflies . These plants are often used in butterfly gardening and monarch waystations in an effort to help increase the dwindling monarch population. However, some milkweed species are not suitable for butterfly gardens and monarch waystations. For example, A. curassavica , or tropical milkweed, is often planted as an ornamental in butterfly gardens outside of its native range of Mexico and Central America . Year-round plantings of this species in

238-648: A pair of pollen sacs can be pulled free when the pollinator flies off, assuming the insect is large enough to produce the necessary pulling force (if not, the insect may become trapped and die). Pollination is effected by the reverse procedure, in which one of the pollinia becomes trapped within the anther slit. Large-bodied hymenopterans (bees, wasps) are the most common and best pollinators, accounting for over 50% of all Asclepias pollination, whereas monarch butterflies are poor pollinators of milkweed. Asclepias species produce their seeds in pods termed follicles . The seeds, which are arranged in overlapping rows, bear

272-592: A plant-based alternative to down and promote the growth of milkweed in areas where it has declined, though there is some concern that the environmental impacts could be negative if monoculture is used. Asclepias is also known as "Silk of America" which is a strand of common milkweed ( A. syriaca ) gathered mainly in the valley of the Saint Lawrence River in Canada . Milkweed floss can be used in thermal insulation and acoustic insulation. The floss

306-412: A ready example. Genera studied and known to contain such glycosides include Acokanthera , Apocynum , Cerbera , Nerium , Thevetia and Strophanthus . Rauvolfia serpentina (Indian snakeroot) contains the alkaloid reserpine , which has been used as an antihypertensive and an antipsychotic drug but its adverse effects limit its clinical use. Catharanthus roseus yields alkaloids used in

340-575: A time (singly) with each occurrence on alternating sides of the stem, but usually occur in pairs (and rarely in whorls ). When paired, they occur on opposite sides of the stem (opposite), with each pair occurring at an angle rotated 90° to the pair below it ( decussate ). There is no stipule (a small leaf-like structure at the base of the leaf stem), or stipules are small and sometimes finger-like. Flowers have radial symmetry ( actinomorphic ), and are borne in heads that are cymes or racemes , or are solitary in axils. They are perfect (bisexual), with

374-425: A typical tripartite style which divides into three zones (specialised for pollen deposition, viscin secretion, and the reception of pollen). The fruit is a drupe , a berry , a capsule , or a (frequently paired) follicle . The seeds are often winged or have appendages of long silky hairs. As of 2012, the family was described as comprising some 5,100 species, in five subfamilies: The former family Asclepiadaceae

SECTION 10

#1732773163238

408-452: Is a small genus of the flowering plant family Apocynaceae . Its name comes from Ancient Greek ἀπόκυνον apókunon , from ἀπο- apo- "away" and κύων kúōn "dog", referring to dogbane ( Cionura erecta ), which was used to poison dogs. The genus is native to North America , temperate Asia , and southeastern Europe . Apocynum species are used as food plants by the larvae of some Lepidoptera species, including

442-523: Is also highly buoyant and water-repellent, but absorbs oil readily. Due to its oil-absorbing properties, it can be used for oil spill cleanup. Milkweed latex contains about two percent latex, and during World War II both Nazi Germany and the US attempted to use it as a source of natural rubber , although no record of large-scale success has been found. Many milkweed species also contain cardiac glycoside poisons that inhibit animal cells from maintaining

476-651: Is an antihypertensive drug used in the treatment of high blood pressure. Many genera are grown as ornamental plants , including Amsonia (bluestar), Nerium (oleander), Vinca (periwinkle), Carissa (Natal plum), Allamanda (golden trumpet), Plumeria (frangipani), Thevetia , Mandevilla (Savannah flower), and Adenium (desert-rose). In addition, the genera Landolphia , Carpodinus , and Mascarenhasia have been used as commercial sources of inferior rubber. (See Congo rubber ) There are limited dietary uses of plants from this family. The flower of Echites panduratus (common name: loroco )

510-460: Is considered a subfamily of Apocynaceae and contains 348 genera. A list of Apocynaceae genera may be found here . Many species are tall trees found in tropical forests, but some grow in tropical dry ( xeric ) environments. Also perennial herbs from temperate zones occur. Many of these plants have milky latex, and many species are poisonous if ingested, the family being rich in genera containing alkaloids and cardiac glycosides , those containing

544-738: Is edible. Carissa (Natal plum) produces an edible fruit, but all other parts of the plant are poisonous. The genus Apocynum was reportedly used as a source of fiber by Native Americans. The aromatic fruit juice from Saba comorensis (syn. Landolphia comorensis , the Bungo or Mbungo fruit ) is used as a drink. Finally, ethnopharmacologic and ethnotoxicologic uses are also known. The roots of Tabernanthe iboga and certain Voacanga species have traditionally been used ceremonially as hallucinogens in Africa. The ibogaine -type alkaloids responsible for

578-399: Is grouped into complex structures called pollinia (or "pollen sacs"), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower-visiting insects , such as bees , wasps , and butterflies , slip into one of the five slits in each flower formed by adjacent anthers . The bases of the pollinia then mechanically attach to the insect, so that

612-562: Is included in Apocynaceae according to the Angiosperm Phylogeny Group III ( APG III ) modern, largely molecular-based system of flowering plant taxonomy. An updated classification, including 366 genera, 25 tribes, and 49 subtribes, was published in 2014. 376 genera are currently accepted. Species in this family are distributed mainly in tropical regions: Several genera are preferred larval host plants for

646-433: Is most often suggested to grow milkweeds that are native to the geographical area they are planted in to prevent negative impacts on monarch butterflies. Monarch caterpillars do not favor butterfly weed ( A. tuberosa ), perhaps because the leaves of that milkweed species contain very little cardenolide . Some other milkweeds may have similar characteristics. Milkweeds are not grown commercially in large scale, but

680-673: The Queen Butterfly ( Danaus gilippus ). Many species of plants from the family Apocynaceae have some toxicity, with some being extremely poisonous if parts are ingested, or if they are not handled properly. Genera containing cardiac glycosides — Cerbera , Nerium , Asclepias , Cascabela , Strophanthus , Acokanthera , Apocynum , Thevetia , etc.—have therapeutic ranges, but are often associated with accidental poisonings, in many cases lethal (see below). Alkaloid -producing species like Rauvolfia serpentina , Catharanthus roseus , and Tabernanthe iboga are likewise

714-649: The United States are controversial and criticised, as they may lead to new overwintering sites along the U.S. Gulf Coast and the consequent year-round breeding of monarchs. This is thought to adversely affect migration patterns, and to cause a dramatic build-up of the dangerous parasite, Ophryocystis elektroscirrha . New research also has shown that monarch larvae reared on tropical milkweed show reduced migratory development (reproductive diapause), and when migratory adults are exposed to tropical milkweed, it stimulates reproductive tissue growth. Because of this, it

SECTION 20

#1732773163238

748-468: The family Asclepiadaceae, which is now classified as the subfamily Asclepiadoideae of the dogbane family, Apocynaceae . The genus was formally described by Carl Linnaeus in 1753, who named it after Asclepius , the Greek god of healing. Members of the genus produce some of the most complex flowers in the plant kingdom, comparable to orchids in complexity. Five petals reflex backwards revealing

782-468: The mouse moth and the queen butterfly . Apocynum cannabinum is used as a source of fiber by Native Americans . Apocynum venetum ( Chinese : 羅布麻 ) is used as an herbal tea in China . Dogbane contains cymarin , a cardiotonic agent formerly used to treat cardiac arrhythmia in humans. Almost 300 names have been proposed in the genus for species, subspecies, and forms. As of 2019 , only

816-410: The coma (the "floss") are hollow and coated with wax, and have good insulation qualities. During World War II , more than 5,000 t (5,500 short tons) of milkweed floss was collected in the US as a substitute for kapok in life jackets. Milkweed is grown commercially as a hypoallergenic filling for pillows and as insulation for winter coats. Using milkweed floss for these purposes could provide

850-561: The following five species and hybrids are currently recognized, with several subspecies and varieties accepted for A. androsaemifolium and A. venetum (see their respective species pages). Asclepias See List of Asclepias species 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

884-415: The latter often finding use as arrow poisons. Some genera of Apocynaceae, such as Adenium , bleed clear sap without latex when damaged, and others, such as Pachypodium , have milky latex apart from their sap. The dogbane/milkweed family includes annual plants, perennial herbs, stem succulents, woody shrubs, trees, or vines. Most exude a milky latex when cut. Leaves are simple . They may appear one at

918-545: The monarch butterfly, Danaus plexippus . The OE parasite causes holes to form in the wings of fully developed monarch butterflies. This causes weakened endurance and an inability to migrate. The parasite only infects monarchs when they are larvae and caterpillars, but the detriment is when they are in their butterfly form. By contrast, some species of Asclepias are extremely poor sources of cardenolides, such as Asclepias fascicularis , Asclepias tuberosa , and Asclepias angustifolia . The leaves of Asclepias species are

952-856: The plants have had many uses throughout human history. Milkweeds have a long history of medicinal, every day, and military use. The Omaha people from Nebraska , the Menomin from Wisconsin and upper Michigan , the Dakota from Minnesota , and the Ponca people from Nebraska , traditionally used common milkweed ( A. syriaca ) for medicinal purposes. The bast fibers of some species can be used for rope. The Miwok people of northern California used heart-leaf milkweed ( A. cordifolia ) for its stems, which they dried and used for cords, strings and ropes. The fine, silky fluff attached to milkweed seeds, which allows them to be distributed long distances on

986-421: 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 . The Asclepias genus contains over 200 species distributed broadly across Africa, North America, and South America. It previously belonged to

1020-469: The psychoactivity of these plants have been studied with regard to the treatment of drug addiction. The juice of Acokanthera species such as A. venenata and the milky juice of the Namibian Pachypodium have been used as poison for arrow tips. Many species are ornamental in gardens or as houseplants. Apocynum Apocynum , commonly known as dogbane or Indian hemp ,

1054-461: The source of compounds with therapeutic ranges, but which have significant associated toxicities if not taken in appropriate doses and in controlled fashion. (See below) Several members of the family Apocynaceae have had economic uses in the past. Several are sources of important natural products —pharmacologic tool compounds and drug research candidates, and in some cases actual prescription drugs. Cardiac glycosides , which affect heart function, are

Apocynaceae - Misplaced Pages Continue

1088-465: The stigmatic slits and die. Milkweeds are also the larval food source for monarch butterflies and their relatives, as well as a variety of other herbivorous insects (including numerous beetles , moths , and true bugs ) specialized to feed on the plants despite their chemical defenses . Milkweeds use three primary defenses to limit damage caused by caterpillars : hairs on the leaves ( trichomes ), cardenolide toxins, and latex fluids. Data from

1122-459: The treatment of cancer. Tabernanthe iboga , Voacanga africana , and Tabernaemontana undulata contain the alkaloid ibogaine , which is a psychedelic drug which may help with drug addiction, but which has significant adverse effects, with ibogaine being both cardiotoxic and neurotoxic. Ajmalicine , an alkaloid found in Rauvolfia spp., Catharanthus roseus , and Mitragyna speciosa ,

1156-456: The wind, is known as floss. Milkweed floss is incredibly difficult to spin due to how short and smooth the filaments are, but blending it with as little as 25% wool or other fiber can produce workable yarn. A study of the insulative properties of various materials found that milkweed floss was outperformed by other materials in terms of insulation, loft, and lumpiness, but it scored well when mixed with down feathers. The milkweed filaments from

#237762