The Tampico Plant (Parthenium incanum) is a resilient perennial shrub native to the arid and semi-arid regions of the Southwestern United States and Mexico. Also known as Mariola or New Mexico rubber plant, it belongs to the Asteraceae family, which includes asters and daisies. Its hardiness allows it to thrive in challenging conditions.
Identifying the Tampico Plant
The Tampico Plant grows as a compact, branched sub-shrub, reaching 1 to 3 feet in height and width. Its foliage is grayish-white due to a dense covering of fine, woolly hairs, which helps reflect sunlight and conserve moisture. The leaves are simple, alternate, often pinnately lobed with rounded segments, measuring about 1 inch long by 0.5 inch wide, and emit a pleasant aroma when disturbed.
Small, white, daisy-like flowers emerge in clusters from July to October. These flower heads are about 1/4 inch wide, with tiny ray and disc florets. It inhabits dry gravelly slopes, rocky outcroppings, and canyons, particularly in limestone and caliche soils, at elevations from 2,500 to 6,000 feet.
Growing Tampico Plant
The Tampico Plant thrives in full sun exposure. Adequate light promotes robust growth and flowering. It adapts to various soil types, preferring well-draining conditions like rocky, sandy, or caliche soils. Proper drainage is important to prevent waterlogging and root rot.
Once established, Parthenium incanum exhibits significant drought tolerance, requiring minimal supplemental water. Watering once a week might be sufficient, allowing the soil to dry completely between applications. The plant is well-suited to hot, dry climates and tolerates temperatures down to about 15°F.
Fertilization is generally not a regular requirement, especially in gardens with adequate soil. If soil fertility is low, a balanced fertilizer can be applied sparingly during active growth to support health and flowering. Light pruning maintains the plant’s shape or removes dead or damaged stems. Pruning can be done in early to late spring, with clean cuts above a bud to prevent disease.
Propagate using seeds or stem cuttings. Seeds can be surface-sown in well-draining mix. Stem cuttings, 4-6 inches long, taken in spring, can be rooted in a similar medium, sometimes with rooting hormone.
Benefits and Traditional Uses
The Tampico Plant is valued in landscaping for its drought-tolerant and low-maintenance qualities, making it ideal for xeriscaping and native plant gardens. Its compact growth habit and grayish-white foliage provide textural interest in arid landscapes. The plant has historical significance in traditional medicinal practices.
Indigenous groups, such as the Jicarilla Apache, traditionally used Mariola leaves, prepared by boiling, to create solutions for various ailments, including discomfort in pregnant women. Its aromatic qualities also suggest folk medicine use. Beyond medicine, Parthenium incanum contains rubber compounds and is a potential source of natural rubber, similar to guayule. While guayule yields more rubber, Mariola still contributes.
Important Considerations
Individuals sensitive to plants in the Asteraceae family, like common ragweed, may experience allergic reactions to the Tampico Plant. Contact can cause allergic contact dermatitis (skin irritation) or respiratory issues, due to sesquiterpene lactones in its leaves, stems, and pollen. Airborne particles, including pollen and dried leaves, trigger these sensitivities.
Though generally low in toxicity, caution is advised around pets and small children to prevent accidental ingestion. While not highly invasive, Parthenium incanum can self-seed in favorable conditions. Removing spent flower heads can manage its spread. Monitor growth to prevent dominance.