Asystasia gangetica
(chinese violet)

Preferred Common Name

• chinese violet

Other Scientific Names

• Asystasia coromandeliana Nees
• Justicia gangetica L.

International Common Names

• English: creeping foxglove; ganges primrose; philippine violet
• Spanish: asistasia; coromandel
• French: herbe le rail; herbe piment; herbe pistache
• Chinese: kuan ye shi wan cuo

Local Common Names

• Malaysia: rumput nyonya
• Mauritius: herbe pistache
• South Africa: asystasia; creeping foxglove
• Thailand: baya; yaya

EPPO code

• ASYCO (Asystasia gangetica)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Scrophulariales
•                         Family: Acanthaceae
•                             Genus: Asystasia
•                                 Species: Asystasia gangetica

The family Acanthaceae includes about 4000 species widespread in both New and Old World Tropics. This family includes a range of morphological diversity, habitats, and biogeographic patterns. The genus Asystasia includes about 40 species of paleotropical origin (Acevedo-Rodríguez, 2005). For A. gangetica two subspecies have been identified: A. gangetica subsp. gangetica and A. gangetica subsp. micrantha. The original range of the subspecies is unclear, but it is likely that A. gangetica subsp. gangetica was limited to Asia, and A. gangetica subsp. micrantha was limited to Africa (Ismail and Shukor, 1998).

Perennial herbs, erect, decumbent, or clambering; 1-3 m in length. Stems quadrangular. Leaves opposite; blades simple, with numerous linear cystoliths on the upper surface, the secondary veins conspicuous; stipules absent. Flowers bisexual, zygomorphic, arranged in spikes on axillary branches. Calyx green, 5-7 mm long, the sepals lanceolate; corolla asymmetrically funnel-shaped, light yellow or pale violet, 2.3-5 cm long, with glandular hairs on the outer surface; stamens and pistil inserted on the floral tube. Capsules ellipsoid or club-shaped, 2-2.5 cm long, light brown when ripe, densely covered with glandular hairs; seeds 2-4 light brown, with irregular margins, lenticular (Acevedo-Rodríguez, 2005).

A. gangetica was introduced as an ornamental plant into the Caribbean islands of Martinique, Guadalupe, St. Vincent and Barbados as early as 1898. Ignaz Urban, in the Symbolae Antillanae reported this species as a “culta et quasi spontanea” for these islands. This species was reported for Puerto Rico for the first time by Liogier and Martorell in 1982 (although collected in 1963) as “cultivated and escaped in moist districts” and for the Virgin Islands by Acevedo-Rodríguez in 1996 as “in gardens or escaped in disturbed areas”. In Puerto Rico, this species is known from the northern half of the island where it is considered as “quite common” (Acevedo-Rodríguez, 2005). A. gangetica was also introduced in Hawaii and in French Polynesia where it has been classified as a “potential problematic species” and by 2002 this species was included in the Global Compendium of Weeds (http://www.hear.org/gcw/). In Australia since 1998 the subspecies A. gangetica micrantha is on the National Environmental Alert List (Ismail and Shukor, 1998) and must be reported when found. In Florida it has been listed as an invasive and noxious weed since 1999 (USDA-NRCS, 2012).

Soil drainage

• free
• impeded
• seasonally waterlogged

Soil texture

• heavy
• light
• medium

A. gangetica is dispersed by seeds and by rhizomes. Seeds are dispersed from explosive capsules.

A. gangetica has been identified as a weed which can smother native plants where it has been introduced. This is possibly due to the fact that this species is a facultative climber and forms dense colonies. Further studies are needed to identify the mechanisms.

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerant of shade
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Fast growing
• Reproduces asexually

• Ecosystem change/ habitat alteration

• Highly likely to be transported internationally deliberately

In Africa (South Africa, Nigeria, Kenya, and Tanzania) the leaves are eaten as a vegetable (e.g. Mepba et al., 2007) and used as an herbal remedy in traditional medicine. The leaves are used in Nigeria for the treatment of asthma (Akah et al., 2003). It is also used as an ornamental plant in countries of the Neotropics.