Overview
Tetramolopium arenarium (Gray) Hbd. is a species of flowering plant in the sunflower family, endemic to the Hawaiian Islands. It is commonly known as Akia to the locals.
Appearance
The Tetramolopium arenarium is a small, perennial shrub that usually grows up to a height of 20 cm. The plant has hairy branches, and its leaves are small and oval, measuring about 1 cm. The flowers of this plant are daisy-like, with yellow or white petals surrounding a central yellow disc. The plant blooms from December to May.
Uses
The Tetramolopium arenarium has various uses. In Hawaiian traditional medicine, it is used to treat various ailments, including fever, cough, and cold. Its leaves and flowers are used to relieve stomachache and indigestion. The plant's extract is also used as a flavoring agent in food and drinks.
The plant is a favorite among horticulturists and is grown as an ornamental plant in gardens and homes worldwide.
Threats
The Tetramolopium arenarium is categorized as critically endangered by the International Union for Conservation of Nature due to habitat loss and invasive species. This plant is restricted to a few isolated populations, making it highly vulnerable to extinction.
Efforts are ongoing to conserve Tetramolopium arenarium's habitat and protect it from invasive species that pose a significant threat to its survival.
Light Requirements
The Tetramolopium arenarium typically grows in open, sunny areas in its native habitat and thus requires high levels of bright, direct light to thrive. When grown indoors, the plant requires exposure to direct sunlight or grow lights for at least 6-8 hours a day.
Temperature Requirements
The Tetramolopium arenarium is native to dry, arid regions in Hawaii and thus prefer warm temperatures. They grow best in temperatures between 65-85°F. Temperatures below 50°F can cause damage to the plant and should be avoided.
Soil Requirements
The Tetramolopium arenarium prefers well-draining soil and can tolerate a pH range between 5.5-7.5. A mixture of sand, perlite, and peat moss can help provide the necessary drainage for the plant to thrive. The plant is also tolerant of nutrient-poor and rocky soils typical of its native habitat.
Cultivation Methods
Tetramolopium arenarium, also referred to as Na`ena`e kuahiwi, is a native shrub to Hawaii that thrives in full sun and well-draining soil. For optimal growth, it is recommended to include organic matter in the soil before planting. The shrub can tolerate a range of soil pH levels but prefers a slightly acidic to neutral pH (6.0-7.0).
Watering Needs
The watering needs of Tetramolopium arenarium vary depending on the environmental conditions. The plant requires moderate watering during the establishment phase and occasional watering in subsequent phases. Overwatering can lead to root rot, which may cause permanent damage to the plant. One way to know that the plant requires watering is to check the soil moisture content using a moisture meter.
Fertilization
Applying fertilizer can improve the growth and overall health of Tetramolopium arenarium. It is recommended to fertilize the soil with nitrogen-based fertilizers during the growing season. However, it is essential to avoid overfertilizing, as this can lead to excessive foliage growth at the expense of flower production.
Pruning
The pruning of Tetramolopium arenarium is essential for maintaining the shrub's shape, removing any dead or damaged stems, and encouraging new growth. It is recommended to prune the shrub after the blooming period to prevent interfering with the shrub's flowering. Use sterile pruning tools to avoid transferring diseases to the plant, and prune the shrub to the desired size and shape using appropriate techniques.
Propagation of Tetramolopium arenarium
Tetramolopium arenarium, also known as beach heliotrope or Hawaiian sea heliotrope, is a beach shrub that is native to Hawaii. It grows up to 1 meter tall and has purple and white flowers that bloom from August to December. The plant is well-known for its ability to grow in poor soil and harsh conditions. Here are the propagation methods for Tetramolopium arenarium:
Seed Propagation
The most common propagation method for Tetramolopium arenarium is through seeds. The seeds can be collected from the plant after the flowers have faded and the seed pods have dried. The collected seeds should be stored in a cool and dry place until they are ready to be sown.
To sow the seeds, they should be planted in a well-draining potting mix. The soil should be kept moist but not overly wet. The seeds should be placed in a warm, sunny spot and should germinate in 2-3 weeks.
Cutting Propagation
Tetramolopium arenarium can also be propagated by taking stem cuttings. The cuttings should be taken from the plant in late spring or early summer. The stem cuttings should be around 5 inches long and have at least two nodes.
The cuttings should be dipped in rooting hormone and then planted in a well-draining potting mix. The soil should be kept moist and the cutting should be placed in a warm, shaded spot. Root growth should occur within 2-3 weeks.
Division Propagation
Tetramolopium arenarium can also be propagated through division. This method involves dividing the plant into smaller sections and then planting them individually.
The plant should be carefully dug up and divided into sections, making sure that each section has a good root system. The divided sections should be planted in a well-draining potting mix and kept moist. The newly planted sections should be kept in a warm, shaded spot until they establish new growth.
Disease Management
Tetramolopium arenarium is known to be susceptible to fungal and bacterial infections. Powdery mildew and gray mold are the most common diseases that affect this plant. Powdery mildew presents as a white, powdery coating on the leaves, while gray mold appears as a grayish-brown fuzzy growth. To manage these diseases, it is important to promote good air circulation around the plant. Avoid watering the leaves and provide adequate spacing between plants. Prune out infected parts of the plant and dispose of them properly. Fungicides can also be applied, but be sure to follow the manufacturer's instructions carefully.
Pest Management
Several pests may attack Tetramolopium arenarium, including aphids, spider mites, and mealybugs. Aphids are tiny sap-sucking insects that can cause severe damage to the plant. Spider mites and mealybugs can also damage the plant by feeding on the leaves. To manage these pests, first, try to remove them by hand or with a strong stream of water. You can also apply insecticidal soaps or oils, which suffocate the pests. Be sure to follow the manufacturer's instructions carefully and apply the treatment to both the tops and bottoms of the leaves.
