Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Tropical soda apple
Solanum viarum

USDA Symbol:SOVI2
ITIS TSN:505273
Presence:Species of Concern
Habitat:Terrestrial
Native Range:Brazil and Argentina
Toxic Characteristics
While not toxic, acts as a vector for viral diseases easily transmitted to other plants.
Geographic Distribution
Most common in the Southeastern U.S. from Florida west to Alabama, and north to Tennessee and Virginia. An established population was discovered in an East Texas (Jasper County) pasture in 2005. No established populations are known to exist in the Houston-Galveston region.
Introduction Pathways
Introduced by unknown means to southern Florida in the early 1980s. Spreads via seed dispersal by livestock, machinery, and hay.
Specific Primary Habitats
High preference to disturbed sandy loam soil. Thrives in heavily grazed pastures. Also found in ditches, agricultural fields, and can spread to forested areas.
Identifying Characteristics
This herbaceous perennial is generally bushy with thorny stems. Leaves are alternate, simple, triangular, mildly lobed, and covered with fine soft hairs. Flowers are white and 5-petaled, occurring in small terminal clusters. Immature fruit is spherical, 0.8-1.2 inches wide, and green mottled with white spots. Fruits resemble miniature watermelons and turn yellow when mature.
Reproduction Characteristics
Reproduction depends on high seed production (200-400 seeds per fruit, of which 75% may germinate) and animal dispersion typically by cattle, deer, wild hogs, or birds. Scarring of seeds promotes germination. Fruits primarily from September through May; fruits are rarely seen during the summer.
Growth Characteristics
A fast growing plant, tropical soda apple reaches maturity 3-4 months after germination. Plants that are cut to the ground will readily resprout from an established root system.
Ecological, Economic, or Social Impact
Tropical soda apple invades pastures and fields, overtaking native grass communities. It carries several viral diseases, and in agricultural systems poses a threat to crops of vegetables which are members the same family (Solanaceae), such as tomatoes. Foliage and stems are unpalatable to livestock and therefore can reduce feeding capacity of pastures. Thorny stems can prevent livestock from moving into shady areas during periods of high heat.
Control
Most important is the prevention of contamination of machinery and hay with seeds, and eradicating or mowing plants before they fruit. Triclopyr is an effective chemical agent, and bacterial agents have also demonstrated effective control.

Native Species Alternatives
Below is a list of alternative plants that are native to the area:
  • American Beautyberry (Callicarpa americana)
  • Turk's Cap (Malvaviscus arboreus)
  • Coralberry (Symphoricarpos orbiculatus)
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail.
Botanist Charles T. Bryson clips tropical soda apple plants in field experiments. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1316013.
Botanist Charles T. Bryson clips tropical soda apple plants in field experiments. Photo courtesy of Peggy Greb, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1316013.
Cluster of immature fruit of the tropical soda apple with thorns on stem. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1624037.
Cluster of immature fruit of the tropical soda apple with thorns on stem. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 1624037.
Cluster of immature fruit of the tropical soda apple. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2254056.
Cluster of immature fruit of the tropical soda apple. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2254056.
Close-up of flowers and developing fruit of tropical soda apple. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2254059.
Close-up of flowers and developing fruit of tropical soda apple. Photo courtesy of Charles T. Bryson, USDA Agricultural Research Service, www.forestryimages.org; Image Number 2254059.
Scattered bushes of the tropical soda apple invading a pasture. Photo courtesy of J. Jeffrey Mullahey, University of Florida, www.forestryimages.org; Image Number 4054010.
Scattered bushes of the tropical soda apple invading a pasture. Photo courtesy of J. Jeffrey Mullahey, University of Florida, www.forestryimages.org; Image Number 4054010.
A single bush of the tropical soda apple. Photo courtesy of J. Jeffrey Mullahey, University of Florida, www.forestryimages.org; Image Number 4054012.
A single bush of the tropical soda apple. Photo courtesy of J. Jeffrey Mullahey, University of Florida, www.forestryimages.org; Image Number 4054012.
Tropical soda apple seedling from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Tropical soda apple seedling from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Foliage and flowers of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Foliage and flowers of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Mature fruit (with cross-section showing seeds) of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Mature fruit (with cross-section showing seeds) of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Mature fruit of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Mature fruit of tropical soda apple from Jasper County, Texas. Photo courtesy of Mary Ketchersid.
Page Updated/Reviewed: 07/14/2010 8:33 AM
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