Anoda is a genus of flowering plants belonging to the Malveae tribe of the mallow family. The most common type is Anoda cristata, which has the upright stems and triangular leaves that are prototypical of all other types. These plants are considered an herb, ornamental plant, or weed, depending on the variety. They are found in the wild from the south-central part of the United States to Mexico, and exist as an introduced plant in Australia. Plant seedlings continuously emerge after rainfall and grow in irrigated land during most of the season, but are killed by frost during winter.
These plants have erect and hairy stems that can grow from approximately 1 to 2.5 feet (30 to 75 cm) in height. The young leaves are oblong in shape, but become triangular as they mature. A leaf consists of three to five lobes and has a hairy texture and reddish color near the stem. Generally, Anoda flowers are cup-shaped and solitary. Each flower of all varieties consist of either six or seven petals that range in color from blue, yellow, to white.
In Mexico, Anoda — or halachas as they are called there — are used as herbs for culinary and medicinal purposes. Both flower and leaf can be eaten. They are used to season squash with garlic and onions. The different parts are also used in traditional medicine to cure reproductive system ailments in women, such as dysmenorrhea.
Anoda lavateroides and A. cristata have colorful flowers which make them popular as ornamental plants. They are usually planted as border plants or as highlights in a garden. Dead flowers should be cut to prevent the plant from taking over other plants in the garden. The aggressive growth of Anoda can cause them to become weeds on plantations and farms.
The destructive weed growth of these plants, specifically Anoda cristata, was first seen in New Mexico and Arizona during the 1950s. By the 1980s, it spread as a troublesome and invasive weed in the southern region of the United States, affecting many cotton and soybean farms there. This type also affects peanuts and grains, as well as pasture land in Australia, where they are not thought of as an endemic species.
These flowering plants need plenty of sun to grow, but they wilt under intense heat. Anoda also tend to grow faster in irrigated areas and areas with abundant rainfall, such as mountain highlands. Large patches of Anoda plants grow all year round, except during winter when they are susceptible to frost damage.