Cryptostegia madagascariensis
(Madagascar rubbervine)

Preferred Scientific Name

• Cryptostegia madagascariensis Bojer ex Decne.

Preferred Common Name

• Madagascar rubbervine

Other Scientific Names

• Cryptostegia glaberrima Hochr.
• Cryptostegia madagascariensis var. glaberrima (Hochr.) Marohasy & P.I. Forst
• Cryptostegia madagascariensis var. septentrionalis Marohasy & P.I. Forst.

International Common Names

• English: devil's claw vine; palay rubbervine; purple allamanda; rubber vine
• Spanish: vid de caucho

Local Common Names

• Brazil: unha do diabo
• El Salvador: vid de goma
• Mexico: vid de goma
• Puerto Rico: canario morado falso
• Saint Lucia: lèt makak; zong makak

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Gentianales
•                         Family: Apocynaceae
•                             Genus: Cryptostegia
•                                 Species: Cryptostegia madagascariensis

C. madagascariensis is native to the north-western coast of Madagascar (USDA-ARS, 2012). It is closely related to C. grandiflora, the only other species in the genus. Currently, the genus Cryptostegia belongs to the family Apocynaceae, but previously was classified within Asclepiadaceae. Apocynaceae is a monophyletic family that includes 415 genera and about 4555 species of perennial herbs, shrubs, and vines distributed broadly within tropical and subtropical areas (Stevens, 2012). Hybrids of these two species with intermediate floral and vegetative morphology have been identified in Madagascar (ISSG, 2012).

C. madagascariensis is a twining woody vine or scandent shrub, 6-8 m in length, with abundant milky latex. Stems are cylindrical, glabrous, reddish brown, with few lenticels. Leaves are opposite; blades 4-10 × 2-4.7 cm, elliptical, oblong, or ovate, coriaceous, glabrous, the apex short-acuminate, obtuse, or rounded. The margins are entire; venation pinnate, with14-16 pairs of secondary veins; upper surface dull; lower surface pale, with obscure venation; petioles glabrous, 0.6-1.5 cm long; stipules minute, intrapetiolar. Flowers are arranged in pedunculate cymes; bracts foliaceous, lanceolate, approximately 5 mm long. Calyx green, campanulate, the sepals lanceolate, pubescent, 0.5-1.5 cm long; corolla 3-6 cm long, violet, the tube darker inside, the lobes abaxially whitish in the overlapping portion; corona with 5 simple lobes, approximately 1 cm long. Two follicles, divergent, brown when mature, 5.8-13 cm long, woody. Seeds are reddish brown, ovate-lanceolate, 3 mm long, with long, cream colored silky hairs (Acevedo-Rodríguez, 2005).

The closely related species Cryptostegia grandiflora and C. madagascariensis are very similar and were probably introduced together into tropical and subtropical countries, first as ornamentals and later planted for rubber production. Currently, C. madagascariensis is widely distributed in India, Kenya, Brazil, Hawaii, Australia and the West Indies and it has become invasive in Hawaii, Brazil, the West Indies (Puerto Rico, Virgin Islands, St Lucia, Montserrat, Anguilla), and Australia.

In Australia, by 2002 this species was listed as a Class 3 invasive species under the Land Protection Act and the sale or supply of this species is prohibited and the removal from environmentally significant areas is required (Australian Weeds Committee, 2012). In Florida, it has been classified as a category II weed (Florida Exotic Pest Plant Council, 2011). For the West Indies, C. madagascariensis was probably introduced as an ornamental in the nineteenth century and was collected by J.A. Stevenson in Puerto Rico 1915 and later in Cuba in 1926. Currently, this species is reported as an “invasive species” on the British Virgin Islands (since 2006), Anguilla (since 2008), Montserrat (since 2008), and St. Lucia (since 2009). In Puerto Rico and US Virgin Islands (St. Croix, St. John, and St. Thomas) C. madagascariensis is classified as an invasive species and is common in thickets and coastal forests (i.e., Guánica, Vieques, Fajardo and Mayaguez; Acevedo-Rodríguez, 2005). According to residents of the islands of St. John, an area ca. 2,000 m² that has been overgrown by this species is the result of one individual introduced about 70 years ago in that area (Acevedo, pers. comm.).

Soil drainage

• free
• seasonally waterlogged

Soil reaction

• acid
• alkaline
• neutral

Soil texture

• heavy
• light
• medium

Special soil tolerances

• saline
• shallow

Seeds are mainly dispersed by wind and water, aided by the silky hairs. Seeds can float for long periods enabling them to be carried along watercourses. In addition, seeds can tolerate prolonged periods of immersion in saline water, facilitating oceanic dispersal (Starr et al., 2003).

C. madagascariensis can smother and out-compete both wild and pasture grasses, being a serious problem in pasture lands in Australia. In addition, it is an expensive problem for ranchers in Australia who must control these plants which are toxic to cattle and horses. This species is toxic to both humans and grazing animals. Lethal effects on cattle have been reported when they have eaten C. madagascariensis and C. grandiflora in the dry season when proper forage is scarce. C. madagascariensis is considered a noxious weed in Australia, Hawaii, and Florida.

C. madagascariensis can form dense monospecific thickets that can out-compete native vegetation (ISSG, 2012). In Australia, this species is invading national parks threatening native and endemic biodiversity (Australian Weeds Committee, 2012). It may also impact forest communities by preventing trees from getting sunlight, because it is able to overtop trees and then shade forests. In Puerto Rico and the Virgin Islands C. madagascariensis can invade coastal dry forests by climbing over trees at the periphery of the forest and slowly spreading further into the interior forest.

• Invasive in its native range
• Proved invasive outside its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Fast growing
• Has high reproductive potential
• Has propagules that can remain viable for more than one year
• Reproduces asexually

• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Host damage
• Infrastructure damage
• Monoculture formation
• Negatively impacts agriculture
• Negatively impacts cultural/traditional practices
• Negatively impacts forestry
• Negatively impacts human health
• Negatively impacts animal health
• Negatively impacts livelihoods
• Negatively impacts aquaculture/fisheries
• Negatively impacts tourism
• Reduced native biodiversity
• Threat to/ loss of endangered species
• Threat to/ loss of native species
• Damages animal/plant products

• Causes allergic responses
• Hybridization
• Interaction with other invasive species
• Rapid growth

• Highly likely to be transported internationally deliberately
• Difficult to identify/detect in the field

C. madagascariensis has been used for the production of rubber in both India and Madagascar. In Madagascar, the species is also used to produce fibres used for making ropes, fish nets and fishing line. C. madagascariensis is a poisonous species and has been used in committing suicide for religious purposes. It is also used in traditional medicine in Madagascar (ISSG, 2012).