Tropaeolaceae Plant Family

About the Tropaeolaceae or Nasturtium Family

The Tropaeolaceae family, also known as the nasturtium family, is a small family of herbaceous plants with about 90 species that are native to the Americas. They are best known for their distinctive shield- leaves and showy, spurred flowers that come in a range of colors from yellow and orange to red and maroon. The leaves and flowers of many species are edible and have a peppery flavor reminiscent of watercress. Nasturtiums are popular garden plants because of their attractive foliage and colorful blooms.

Taxonomy and Classification

The Tropaeolaceae family is a small family of herbaceous flowering plants in the order Brassicales, which also includes the mustard and cabbage families. Within the order, Tropaeolaceae is classified in the family Brassicaceae, along with another closely related family, Resedaceae.

The family Tropaeolaceae consists of one genus, Tropaeolum, which contains about 90 species of annual and perennial herbs that are native to Central and South America. There are no subfamilies or major groups within the family.

Tropaeolaceae is most closely related to the family Resedaceae, both of which have distinctive shield- leaves and flowers with spurs.

Morphology and Characteristics

Plants in the Tropaeolaceae family are herbaceous annual or perennial plants with trailing or climbing stems that can reach up to 3 meters long. The leaves are alternate and are borne on petioles that attach at the center of the leaf blade, creating their distinctive shield- shape. The leaves are typically round to kidney- and can range from 2- cm in diameter.

The showy flowers of Tropaeolaceae are bisexual, meaning they have both male and female reproductive structures, and are typically radially symmetrical. They have five petals that are fused at the base into a tube, and a prominent spur that extends backward from the base of each flower. Flowers may be borne singly or in pairs on long peduncles arising from the stem.

Tropaeolaceae plants produce fruit in the form of a dry, indehiscent nutlet that contains one seed. The seeds are often large and bright in color, making them attractive to birds and other animals for dispersal.

Nasturtiums are known for their peppery taste and have been used in salads and as herbal remedies for centuries. They are also popular garden plants due to their attractive foliage and brightly colored flowers.

Distribution and Habitat

The Tropaeolaceae family is native to Central and South America, where they can be found from Mexico to Argentina. Many species are adapted to subtropical or tropical climates, with a few species able to tolerate colder temperatures.

Tropaeolaceae plants can be found in a variety of habitats, including forests, grasslands, and rocky outcrops. They are particularly well- to disturbed areas, such as roadsides or fields, where they can form dense mats or climb on other vegetation.

Some species of Tropaeolum have been introduced to other parts of the world and have become naturalized in areas with similar climates, such as southern Europe, Africa, Australia, and New Zealand. These introduced species can sometimes escape cultivation and become invasive, outcompeting native vegetation and altering ecosystems.

Economic and Ecological Importance

The Tropaeolaceae family has both economic and ecological importance. Many species are valued as ornamental plants for their attractive foliage and brightly colored flowers. Nasturtiums are particularly popular in gardens and containers due to their low maintenance requirements and their ability to attract beneficial insects like bees and butterflies.

Several species of Tropaeolum, including T. majus and T. tuberosum, are also cultivated as food crops, with the leaves and flowers being used in salads and the seeds being pickled or used as a substitute for capers. Some species have also been traditionally used in herbal medicine to treat various ailments, including respiratory infections and urinary tract infections.

Ecologically, Tropaeolaceae plants play an important role in ecosystems by providing habitat and food sources for pollinators and other animals. They can also contribute to biodiversity by colonizing disturbed areas and helping to prevent erosion.

However, some introduced species of Tropaeolum have become invasive in certain regions, displacing native vegetation and altering natural ecosystems. It is important to closely monitor the spread of these species and control their populations to prevent further damage to the environment.

Notable Species

Some notable species in the Tropaeolaceae family include:

  • Tropaeolum majus: Also known as garden nasturtium, this species is one of the most commonly cultivated members of the family. It is an annual plant that produces bright orange, yellow, and red flowers, as well as edible leaves and flowers with a peppery taste.

  • Tropaeolum peregrinum: This species, also called canary creeper, is a climbing vine with yellow- flowers that have long, thin spurs. It is often grown as a decorative plant in gardens and containers.

  • Tropaeolum tuberosum: Also known as mashua or añ this species is cultivated for its edible tubers, which are similar to potatoes but have a sweeter taste. It is native to the Andean region of South America and has been cultivated for thousands of years by indigenous peoples.

  • Tropaeolum brachyceras: This species is a dwarf plant that forms a mat- ground cover and produces small, bright orange- flowers. It is native to rocky outcrops in Argentina and has been used in traditional medicine to treat respiratory infections.

  • Tropaeolum speciosum: Also called flame flower or scarlet nasturtium, this species is a perennial vine with bright red flowers that resemble flames. It is native to the Andes mountains of Peru and is sometimes grown as an ornamental plant in gardens.

Several species of Tropaeolum are threatened by habitat loss and over- particularly in their native range in the Andes. Conservation efforts are underway to protect these species and their habitats.