The term “bitterbush” refers to several distinct plant species. This common name implies a bitter taste, often linked to the plants’ chemical properties. Understanding the specific plant is important, as “bitterbush” is not a single botanical entity but a shared moniker for different species. This article explores these diverse “bitterbush” plants and their significances.
Identifying Bitterbush
The name “bitterbush” applies to multiple plant species. Among the most commonly referenced are Picramnia pentandra, Simarouba glauca, and Purshia tridentata. Another plant sometimes called bitterbush or groundsel bush is Baccharis halimifolia.
Known as Florida bitterbush or doctor bush, Picramnia pentandra is an evergreen shrub or small tree, growing 6 to 10 meters tall. Its compound leaves have 5 to 9 leathery leaflets, which are reddish when developing. Small, green flowers are arranged in slender, drooping spikes. This plant is dioecious, with male and female flowers on separate individuals. Its fruit is a berry that turns from red to black upon maturity.
Simarouba glauca, also known as paradise-tree or bitterwood, is an evergreen tree growing 12 to 15 meters tall. It has large, pinnately compound leaves with multiple shiny, leathery, oblong leaflets, often reddish when young. Its small, yellow or yellowish-white flowers appear in panicles. The fruit is a purple-black, elongated, oval, fleshy drupe, about 15-20 mm long, which is edible but considered inferior.
Purshia tridentata, commonly called bitterbrush or antelope bitterbrush, is a deciduous shrub growing 1 to 5 meters tall. It has many branches and slender, green, three- to five-lobed leaves, 5 to 20 millimeters long, often clustered on spur shoots. Its small, pale yellow flowers have five petals and produce dry, slender achenes as fruit.
Baccharis halimifolia, also known as eastern baccharis or groundsel bush, is a deciduous shrub growing up to 12 feet tall, sometimes as a small tree. It has simple, alternate, thick, egg-shaped to rhombic leaves, often coarsely toothed. This dioecious plant has male and female flowers on separate individuals. Female plants produce conspicuous snowy-white, cotton-like flower heads in the fall. Its fruit is a pyramid-shaped achene with a cottony, plume-like pappus, aiding wind dispersal.
Where Bitterbush Thrives
Picramnia pentandra is found in tropical and subtropical regions, including Florida, the Caribbean, and northern South America. It grows as an understory shrub or small tree in dry broadleaf evergreen forests. This species prefers well-drained soils and tolerates some salt spray and low light conditions.
Simarouba glauca is native to warm, humid, tropical regions, including Florida, Central America, and the Caribbean. It grows well in various well-drained soils, from sandy to clay, and tolerates mildly acidic to basic pH levels. This tree is shade-tolerant and often found as an understory tree.
Purshia tridentata is native to mountainous areas of western North America, from British Columbia south to New Mexico and west into California. It is well-adapted to arid environments, growing on dry mountainsides, slopes, and well-drained soils. This shrub can grow at high elevations.
Baccharis halimifolia is indigenous to coastal areas of the eastern United States, Canada, and Mexico. It is commonly found in salt marshes, sandy locations, and wet disturbed sites. Highly salt-tolerant, it thrives along brackish shores and inland coastal areas. This species is an ecological generalist, capable of growing in a range of soil types and tolerating both wet and dry conditions. It has become naturalized and invasive in parts of Europe and Australia.
Understanding Bitterbush Properties and Uses
Picramnia pentandra is used in traditional medicine, particularly in the Lucayan Archipelago. A bitter tonic from its leaves and bark addresses colds, flu, dermatological issues, gastrointestinal problems, and respiratory illnesses. It is also used for general strengthening teas.
Simarouba glauca is known for its high concentration of quassinoids, which contribute to its bitter taste and medicinal properties. Traditionally, its leaves and bark treat fevers, malaria, dysentery, and other gastrointestinal issues. Scientific reviews indicate its potential for anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. Beyond medicine, its seeds yield an edible oil for bakery and industrial uses, and its wood is used in construction and for fuel.
Purshia tridentata leaves are an important food source for wildlife. Native Americans traditionally used its leaves as a laxative and to alleviate itching. Its branches were also used as fuel. This shrub is a nitrogen-fixing plant, which enriches the soil.
Baccharis halimifolia contains bioactive compounds. Traditional uses suggest its application in alleviating symptoms of coughs, sore throats, and colds, due to anti-inflammatory properties. Extracts are believed to have antimicrobial and antioxidant effects, useful for skin infections and protecting cells from damage. Some traditional remedies include its use for fevers and as a general tonic, with crushed leaves sometimes applied topically to wounds. It is also cultivated as a hedge or ornamental plant due to its hardiness and autumn flowering.
Potential Concerns and Management
Picramnia pentandra has no widely known hazards. As with any plant used medicinally, proper identification is important before use.
Simarouba glauca contains quassinoids, which can be toxic in high concentrations despite their medicinal properties. Very high doses might affect liver and kidney markers, though lower doses show no significant toxicity. The oil extracted from its seeds is considered edible and free of toxic compounds.
Purshia tridentata is not considered toxic to humans, but its bitter taste makes it unpalatable. It is a valuable forage for wildlife and is not associated with invasive tendencies.
Baccharis halimifolia can be toxic to livestock if consumed in large quantities. Symptoms of toxicity are not widely detailed for humans, but caution is advised.
Beyond toxicity, Baccharis halimifolia is recognized as an invasive species in several regions outside its native range, particularly in Europe and Australia. It produces abundant, wind-dispersed seeds, allowing it to spread rapidly and form dense thickets that outcompete native vegetation, altering habitats and reducing biodiversity. Management often involves manual removal of seedlings and young plants. Chemical control methods exist, but herbicides may not always be highly effective. Biological control agents have also been explored to manage its spread.