Asclepias curassavica

Asclepias curassavica
File:Flower1@TGPH&S,Thumkoor-1.jpg
From near Bangalore
Conservation status
Secure (NatureServe)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Gentianales
Family:	Apocynaceae
Genus:	Asclepias
Species:	A. curassavica
Binomial name
Asclepias curassavica L.
Synonyms
Asclepias nivea var. curassavica (L.) Kuntze

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.

It is grown as an ornamental garden plant and as a source of food for butterflies. Notably, it attracts members of the Danainae subfamily, such as the Monarch and the Queen.

Description

File:Asclepias curassavica221.jpg

Flowers

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. 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).

Cultivation

There are a number of different cultivars with improved flower colors and shorter habit, some have brilliant red, yellow or orange colored flowers. Asclepias curassavica is excellent in butterfly gardens or as a cut flower. However, when the stems or leaves are broken, a poisonous milky sap exudes which can cause eye injury.

Distribution

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

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.

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.

It is considered an exotic plant, but not a weed, at the Meteor Downs South Project near Rolleston, Queensland, Australia.

Chemistry

Asclepias curassavica contains several cardiac glycosides which include asclepin, calotropin, uzarin and their free genins, calactin, coroglucigenin and uzarigenin. It also contains oleanolic acid, ß- sitosterol, and glycosides of asclepin.

Gallery

• Asclepias curassavica234.jpg

  Flower from Flower View

• Asclepias curassavica 002.JPG

  Fruits

• Asclepias curassavica 003.JPG

  Seeds

• Asclepias curassavica0.jpg

  Seed with parachute

• Asclepiascurassavica.jpg

  Seeds close up

• Asclepias curassavica 1854.jpg

  Flower closeup

• Mexican Butterfly Weed Asclepias curassavica Ants 2000px.jpg

  Flowers with ants feeding on the nectar

• Danaus plexippus-caterpillars.jpg

  Monarch caterpillars feeding on Milkweed.

• Milkweed Asclepias curassavica 'Silky Gold' Flowers 2400px.jpg

  Asclepias curassavica 'Silky Gold'

External links

• Jepson Manual (1993) — description of introduced species and non-native California distribution.
• Video of Monarch butterfly larva and adults feeding on Asclepias

• Singh, B. and Rastogi, R.P. 1970. Cardenolides-glycosides and genins. Phytochemistry 9: 315-331.
• Singh, B. and Rastogi, R.P. 1972. Structure of ascelpin and some observations on the NMR spectra of Calotropis glycosides. Phytochemistry 11: 757-762.
• Singh, B. and Rastogi, R.P. 1969. Chemical investigation of Asclepias curassavica Linn. Indian J. of Chem. 7: 1105-1110.