Asclepias curassavica, commonly known as tropical milkweed,[3] is a flowering plant species of the milkweed genus, Asclepias.[4] It is native to the American tropics[5] and has a pantropical distribution as an introduced species. Other common names include bloodflower or blood flower,[3] cotton bush,[6] hierba de la cucaracha,[3] Mexican butterfly weed, redhead,[6] scarlet milkweed,[3] and wild ipecacuanha.[3]

Asclepias curassavica

Secure  (NatureServe)[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Gentianales
Family: Apocynaceae
Genus: Asclepias
Species:
A. curassavica
Binomial name
Asclepias curassavica
Synonyms[2]

Asclepias nivea var. curassavica (L.) Kuntze

It is grown as an ornamental garden plant and as a food source for some butterflies, however it may be harmful to the migration patterns of monarch butterflies when used in gardens outside of its native tropical range.[7] Though public concern for the rapidly declining monarch population increased the demand and commercial availability of milkweed among nurseries in the US, the results have been mixed. While tropical milkweed may effectively sustain monarch larvae, the perennial growth of the plant takes ill effect on the monarchs' migratory patterns and may have other physiological effects.[8] Use of the tropical milkweed in gardens has disrupted monarch migrations notably in California, Texas, Florida, and South Carolina.[9] Unlike the milkweed species native to these locations, the tropical milkweed does not go dormant in the winter causing non-migratory groups of butterflies to form. Planting Asclepias curassavica in nonnative regions therefore remains controversial and criticized. Alternatively, native milkweed species (such as showy milkweed, narrowleaf milkweed, and desert milkweed for California[10]) are suggested for butterfly gardens.[11]

It also attracts other members of the Danainae subfamily, such as the queen.

Collage of arthropods using tropical milkweed (Asclepias curassavica) for nectar or as a hunting ground

Description

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Typical plants are evergreen perennial subshrubs that grow up to 1 m (3.3 ft) tall and have pale gray stems. The leaves are arranged oppositely on the stems and are lanceolate or oblong-lanceolate shaped ending in acuminate or acute tips. Like other members of the genus, the sap is milky. The flowers are in cymes with 10-20 flowers each. They have purple or red corollas and corona lobes that are yellow or orange. Flowering occurs nearly year-round.[5] The 5–10 cm (2.0–3.9 in) long, fusiform shaped fruits are called follicles. The follicles contain tan to brown seeds that are ovate in shape and 6–7 mm (0.24–0.28 in) long. The flat seeds have silky hairs that allow the seeds to float on air currents when the pod-like follicles dehisce (split open).[12]

Cultivation

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There are a number of different cultivars with improved flower colors and shorter habit; some have bright red, yellow or orange colored flowers. Asclepias curassavica is sometimes used in butterfly gardens (see above for concerns for monarchs) or as a cut flower. However, when the stems or leaves are broken, a poisonous milky sap exudes which can cause eye injury.[13]

Distribution

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Asclepias curassavica is described by NatureServe as a "widespread species, ranging from southern North America through Central America and into South America."[1]

It is an introduced species in the US states of California, Florida, Hawaii, Louisiana, Tennessee, and Texas, as well as the US unincorporated territories of Puerto Rico and the United States Virgin Islands.[14]

It has been introduced and naturalized in the Chinese provinces of Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Qinghai, Sichuan, Xizang, Yunnan, and Zhejiang, as well as in Taiwan.[5]

Asclepias curassavica was introduced to Australia prior to 1869 and is widespread in parts of Queensland.[15] It is considered an exotic plant, and a weed, at the Meteor Downs South Project near Rolleston, Queensland, Australia.[16]

Chemistry

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Asclepias curassavica contains several cardiac glycosides,[17] including asclepin,[18] calotropin, uzarin and their free genins, calactin, coroglucigenin and uzarigenin.[19] It also contains oleanolic acid, β-sitosterol, and glycosides of asclepin. The most abundant cardiac glycoside present in Asclepias curassavica leaves is voruscharin, which comprises around 40% of the total cardiac glycoside content in leaves.[20]

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References

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  1. ^ a b Raker, C (1995). "Comprehensive Report Species – Asclepias curassavica". NatureServe Explorer: An online encyclopedia of life [web application]. 7.1. Arlington, Virginia: NatureServe Inc. Retrieved 2014-03-22.
  2. ^ "Synonyms of Tropical Milkweed (Asclepias curassavica)". Encyclopedia of Life. Retrieved 2014-03-22.
  3. ^ a b c d e "Common Names for Tropical Milkweed (Asclepias curassavica)". Encyclopedia of Life. Retrieved 2014-03-22.
  4. ^ "ITIS Standard Report Page: Asclepias curassavica". Integrated Taxonomic Information System. Retrieved 2014-03-22.
  5. ^ a b c "Asclepias curassavica in Flora of China". Flora of China @ eFloras.org. Missouri Botanical Garden. Retrieved 2014-03-22.
  6. ^ a b "Asclepias curassavica". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 5 September 2014.
  7. ^ Howard, Elizabeth; Aschen, Harlen; Davis, Andrew K. (2010). "Citizen Science Observations of Monarch Butterfly Overwintering in the Southern United States". Psyche: A Journal of Entomology. 2010: 1–6. doi:10.1155/2010/689301.
  8. ^ Majewska, Ania A.; Altizer, Sonia (16 August 2019). "Exposure to Non-Native Tropical Milkweed Promotes Reproductive Development in Migratory Monarch Butterflies". Insects. 10 (8): 253. doi:10.3390/insects10080253. PMC 6724006. PMID 31426310.
  9. ^ "Can Milkweed be Bad for Monarchs". 12 January 2013.
  10. ^ Fahy, Claire (2021-06-01). "California's Monarch Butterflies Are Down 99%. Can This Plant Help?". The New York Times. ISSN 0362-4331. Retrieved 2021-06-04.
  11. ^ Clarke, Chris (9 January 2015). "Gardening to Help Monarch Butterflies? Plant Natives". KCET.
  12. ^ Christman, Steve (2004-01-21). "Asclepias curassavica: Floridata". Floridata. Retrieved 2014-03-22.
  13. ^ Hsueh, Kuo-Fang; Lin, Pei-Yu; Lee, Shui-Mei; Hsieh, Chang-Fu (February 2004). "Ocular injuries from plant sap of genera Euphorbia and Dieffenbachia" (PDF). Journal of the Chinese Medical Association. 67 (2): 93–98. PMID 15146906. Archived from the original (PDF) on 2014-06-11. Retrieved 2011-05-01.
  14. ^ "Plants Profile for Asclepias curassavica (Bloodflower)". Plants Database. USDA Natural Resources Conservation Service. Retrieved 2014-03-22.
  15. ^ "Asclepias curassavica (bloodflower)". www.cabi.org. Retrieved 2022-05-06.
  16. ^ Wormington, Kevin; Tucker, Gail; Black, Robert; Campbell, Lorelle (2012). "Flora, fauna and freshwater biota assessment of the Meteor Downs South Project, near Rolleston, Central Queensland" (PDF). EIS and Technical Reports. Gold Coast Quarry: 28. Retrieved 2014-03-30.
  17. ^ Singh, Bhagirath; Rastogi, R.P. (February 1970). "Cardenolides—glycosides and genins". Phytochemistry. 9 (2): 315–331. doi:10.1016/S0031-9422(00)85141-9.
  18. ^ Singh, B.; Rastogi, R.P. (February 1972). "Structure of asclepin and some observations on the NMR spectra of Calotropis glycosides". Phytochemistry. 11 (2): 757–762. doi:10.1016/0031-9422(72)80044-X.
  19. ^ Singh, Bhagirath; Rastogi, R. (1969). "Chemical investigation of Asclepias curassavica Linn". Indian Journal of Chemistry. 7: 1105–1110.
  20. ^ Agrawal, Anurag A.; Böröczky, Katalin; Haribal, Meena; Hastings, Amy P.; White, Ronald A.; Jiang, Ren-Wang; Duplais, Christophe (2021-04-20). "Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds". Proceedings of the National Academy of Sciences. 118 (16): e2024463118. Bibcode:2021PNAS..11824463A. doi:10.1073/pnas.2024463118. ISSN 0027-8424. PMC 8072370. PMID 33850021.
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