Brazilian Verbena, also known as Verbena brasiliensis, is an invasive weed that thrives well in well-drained soils.
The weed is native to South America and perennial in zones 7 to 11 but grows annually in cooler areas.
Brazilian Verbena stands at a height of 3-8 feet and has tall stems that are sharp-cornered with stiff hairs from which loose terminal spikes are where flowers grow.
Scientific Classification
- Kingdom: Plantae
- Phylum: Magnoliophyta
- Class: Magnoliopsida
- Subclass: Asteridae
- Order: Lamiales
- Family: Verbanaceae
- Genus: Verbena
- Species: Verbena Brasiliensis
- Other Names: Brazilian verbena, Brazilian vervain, Verbena brasiliensis
Nativity and Distribution
Verbena brasiliensis is native to South America, specifically Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, Paraguay, and Uruguay. The species is also found in:
- Eastern parts of Australia
- Southern Africa
- Temperate Asia
- North America
- Eastern New South Wales
Physical Characteristics
- Leaves: The leaves are green and are rough to the touch.
- Flowers: The small tubular flowers are numerous and densely arranged into branched, finger-like clusters at the tips of these stems.
- Fruits: The fruits are brown and contained in a capsule.
- Stem: The plant’s main stem leaves have two expanded earlike lobes above the petiole.
- Roots: The weed is tap-rooted or has woody fibrous roots.
Brazilian Verbena has simple leaves arranged on opposite sides of the stem.
They are elliptical with serrated margins, acute tips, and shrunk veins on the upper side that are one inch wide. You’re likely to notice their lacerated coarse hairs, measuring one to three inches in length
Additionally, the plant’s leaves have rigid hairs with bristles on the undersides along the major veins.
Leaves on Brazilian Verbena are mainly at the base of the plant and form a mounded bunch of green lance-shaped leaves with indented margins.
Verbena brasiliensis flowers are violet-blue or purple. They appear as small clusters on long stems 2 to 3 inches in diameter. The flower has five lobes joined near the apex.
The corolla, which is purple-bluish, protrudes from the calyx and bears four stamens. The entire flower is hairy.
When mature, the small fruit may separate into four seeds, mericarps, or nutlets. These seeds are 1.5-1.8 mm long, elongated in shape, and usually brown.
Brazilian Verbena is 3-8 feet in height and has tall stems that are sharp-cornered with stiff hairs from which loose terminal spikes are where the plant’s flowers grow.
Reproduction, Dispersal, & Life Cycle
- Life Cycle: Perennial, but grows as an annual in cooler climates
- Seeds: Seeds are small, triangular in cross-section, and encased in the calyx
- Climate: The plant thrives in 7 to11 zones but also grows in cooler climates
- Dispersal: Seeds are dispersed by animals, wind, or water
Verbena brasiliensis fruits generate four nutlets, two for each carpel. When ripe, the flower’s calyx separates, releasing the seeds.
These seeds are then dispersed by animals such as bees and butterflies, wind, and water. The seeds may also be spread in contaminated agricultural produce.
Uses
This plant is used for garden and ornamental purposes.
Impact on Farms & Environment
Brazilian Verbena is considered an invasive species that displaces native plants, thus disrupting ecological balance.
The plant spreads by seed dispersal by animals, water, and wind, thus contributing to its invasive nature.
Control
The following methods will control Verbena brasiliensis:
Herbicides
The Herbicide Triclopyr 480 has been effective in controlling the weed in South Africa, while Grazon P+D and GrazonNext HL have been tested as effective herbicides for Brazilian verbena in the US.
Hand Pulling
Small infestations can be treated by hand-pulling or digging out the plant’s roots from their base.
Hand-pulling is most effective when the ground is moist in the rainy season.
Lead Editor for Insight Weeds.