Acanthaceae is a family of plants which is also called the Acanthus family. This group is comprised of flowering plants. Most of them are tropical or subtropical, though some are temperate. The group is well known to gardeners; many of the family’s species are popular garden plants.
The family has a well-defined core, but some experts argue about the inclusion of certain plants in Acanthaceae. As a result of these long-standing arguments, literature on the subject will often refer to core, or narrow, and broad versions of the family. The first is limited to the members that are widely accepted by the scientific community, while the second includes some additional plants closely related to the core plants, but that scientists have traditionally placed in different families. One example of a member of broad Acanthaceae that is excluded from the narrow version is the black mangrove, which is sometimes placed in a family by itself and sometimes considered part of the family that includes verbena.
Members of the Acanthaceae family have a few uniting characteristics. They all flower and bear fruit. Inside the fruit, the seeds are held by structures called retinacula, which look like hooks. When the fruit matures, it bursts, spreading seeds around the parent plant. Their flowers have petals fused together and two or four stamens.
Perhaps the most definitive characteristic of this family is its diversity. It has more than 4,000 species, and they are divided into more than 200 genera. Apart from their distinctive fruits, they have a variety of differences from each other. Their pollen grains have different shapes and textures. They grow in the forms of shrubs, trees, bushes and typical garden flowers. Their leaves can be green or colorful, and they often have vibrant flowers.
The majority of the species that make up the Acanthaceae family grow in tropical climates, but sometimes they are found in temperate zones as well. For example, Bear’s Breeches are common garden plants that grow in temperate climates. The plant known as the squirrel tail or shrimp plant is often found in gardens in Hawaii. Both are part of the family.
Members of the Acanthaceae family are often grown decoratively. This is the case for African violets, for example, along with Bear’s Breeches and the shrimp plant. The mint plant is also part of the family, and it is used to create mint flavoring in food.