Commelinaceae Family

About the Commelinaceae or Spiderwort Family

The Commelinaceae family, also known as the spiderwort family, is a group of flowering plants that includes more than 700 species. These plants are typically found in tropical and subtropical regions but can also be found in temperate zones. The family is characterized by its unique floral structures, which have three petals and three sepals, and its leaf arrangements, which are often two-ranked or spirally arranged. Members of the family range from small herbs to vines and shrubs, and many are popular ornamental plants due to their attractive foliage and flowers.

Taxonomy and Classification

The Commelinaceae family belongs to the order Commelinales, which also includes the dayflower family (Commelinaceae) and the bloodwort family (Haemodoraceae). Within the family, there are several subfamilies, including Commelinoideae, Tradescantioideae, and Cartonematoideae. The family is further divided into 40 genera, some of which include Commelina, Tradescantia, and Callisia. Commelinaceae species are characterized by their distinctive floral structures, which have three petals and three sepals, and their leaves, which are often folded or rolled in a unique manner. The family is related to other groups such as Pontederiaceae and Philydraceae, which also have similar leaf arrangements.

Morphology and Characteristics

Commelinaceae species are generally herbaceous perennials, but can also be annuals, vines or shrubs. Their leaves are typically simple and alternate, with a unique folding or rolling trait known as the "involute vernation." This characteristic causes the leaves to wrap around each other in bud, giving them a cylindrical appearance. The flowers of Commelinaceae are composed of three petals and three sepals arranged into a tube-like structure, with six stamens surrounding a single pistil. The flowers are often subtended by two large bracts that are usually brightly colored. Many species in this family have adapted to tolerate low light conditions, by having purple or green leaves to help absorb more light. Additionally, some plants in the Commelinaceae family have been noted for their ability to remove pollutants from the air.

Distribution and Habitat

The Commelinaceae family is widely distributed throughout tropical and subtropical regions of the world, especially in the Americas, Africa, and Asia. The family contains many species native to Central and South America, where they are found in a variety of habitats such as savannas, forests, and wetlands. Members of this family can also be found in other regions such as Madagascar, Australia, and India. Some species in the family have been introduced to other parts of the world, including North America and Europe, either intentionally or accidentally. The distribution of species in this family is influenced by factors such as climate, soil conditions, and human activities. For example, some species are adapted to wet habitats, while others prefer drier environments.

Economic and Ecological Importance

The Commelinaceae family has both ecological and economic significance. Many species in the family serve as food sources for various animals, including insects, birds, and mammals. Some species are also important in maintaining soil stability and nutrient cycling in their native ecosystems. Moreover, some plants in the Commelinaceae family are used for medicinal purposes, such as treating infections, gastrointestinal disorders, and skin conditions.

Many of the species within the Commelinaceae family are also cultivated as ornamental plants due to their attractive foliage and distinctive flowers. For example, certain Tradescantia species and cultivars are commonly grown as houseplants or in outdoor gardens for their colorful leaves and ease of care. The purple heart plant (Tradescantia pallida), is one such popular houseplant species known for its attractive purple foliage.

Some species in the family are also used for commercial purposes. For example, spiderwort (Tradescantia virginiana) has been used in herbal medicine and the fibers from some Commelina species have been used to make textiles and paper. Finally, the study of the Commelinaceae family can provide insights into plant evolution and systematics, helping researchers better understand the relationships between different plant groups and how they have evolved over time.

Notable Species

Some notable species of the Commelinaceae family include:

  1. Tradescantia zebrina: Also known as wandering jew, this species is a popular houseplant grown for its distinctive zebra-striped leaves. It is native to Mexico and Central America.

  2. Commelina benghalensis: This species is a common weed in many parts of the world. It has blue-purple flowers and is known for being difficult to control due to its ability to quickly regenerate from broken stem fragments.

  3. Callisia fragrans: This species is commonly called an Inch Plant or Basket Plant and is grown as an ornamental plant for its attractive green and white striped leaves. It is native to Mexico and Central America.

  4. Tradescantia virginiana: Spiderwort is a woodland wildflower with blue-purple flowers that bloom in spring and summer. It is native to eastern North America and has been used medicinally by Native American tribes.

  5. Cyanotis cristata: This species is known as the "bible plant", referring to the shape of the flower buds, which resemble a small book. It is native to tropical regions of Asia and Africa and is cultivated as an ornamental plant for its showy flowers.

These species have both ornamental and ecological significance, as well as cultural importance in some cases. For example, the spiderwort (Tradescantia virginiana) has been used in traditional medicine, and the wandering Jew (Tradescantia zebrina) has religious significance in some cultures.