Overview of Nototrichium sandwicense var. olokeleanum Sherff
Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff is a shrub native to the Hawaiian Islands. It is a member of the sunflower family, Asteraceae. This plant is commonly known as 'Olokele Canyon Na'u or Na'u Kapa.
Appearance of Nototrichium sandwicense var. olokeleanum Sherff
Nototrichium sandwicense var. olokeleanum Sherff is a densely branched shrub that can grow to a height of 1.5 meters. Its leaves are deeply lobed and green in color, and its stems are densely hairy. The flowers are small, yellow, and arranged in clusters at the tips of the branches. The fruits are small, dry achenes with a pappus of bristles that facilitate wind dispersal.
Uses of Nototrichium sandwicense var. olokeleanum Sherff
The leaves and stems of Nototrichium sandwicense var. olokeleanum Sherff have medicinal properties and are used by the native Hawaiians to treat ailments such as upset stomach, coughs, colds, and fever. The plant also has cultural significance, and its fiber is used to make traditional Hawaiian kapa cloth. The plant is also important in controlling soil erosion and maintaining stream flow in the Olokele Canyon area.
Threats to Nototrichium sandwicense var. olokeleanum Sherff
Like many native Hawaiian plants, Nototrichium sandwicense var. olokeleanum Sherff is threatened by habitat loss and invasive species. Grazing by feral goats and pigs and competition from non-native plants are the major factors contributing to its decline. The plant is listed as an endangered species by the State of Hawaii, and conservation efforts are underway to protect and restore its habitat.
Light Requirements
Nototrichium sandwicense var. olokeleanum thrives in areas with full or partial sunlight exposure. It can also grow well in areas with filtered light. However, too much shade can lead to stunted growth and less flowering.
Temperature Requirements
This plant species prefers warmer temperatures ranging from 68°F to 86°F (20°C to 30°C). It cannot survive in cold temperatures below 50°F (10°C).
Soil Requirements
The plant requires well-draining soils with good aeration to promote proper root growth. The soil should be rich in organic matter, such as composted leaves, and have a slightly acidic pH between 5.5 and 6.5. The plant is adapted to grow in volcanic soils, which are typically well-draining and have low nutrient availability. Therefore, it can tolerate low to moderate fertility soils.
Cultivation Method
The Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff is native to Hawaii and is popularly grown as an ornamental plant due to its stunning appearance. The plant requires well-draining soil, which is rich in organic matter. The ideal location for planting is in a spot with partial shade to full sun exposure.
The recommended planting time for Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff is during the rainy season or the onset of spring. The plant can be propagated using cuttings, which should be dipped in rooting hormone before planting in a well-draining potting mix. The potting mix should be kept moderately moist until the cutting roots well.
Watering Needs
The Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff is a drought-tolerant plant and doesn't require frequent watering. Overwatering can lead to root rot and consequently, plant death. To prevent this, allow the soil to dry out between watering sessions, but avoid allowing it to become bone dry. During the summer months, you need to increase the frequency of watering, but ensure you don't water from overhead as this can lead to fungal diseases.
Fertilization
Fertilization is essential to ensure the Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff plant thrives and produces healthy and vibrant growth. Use a balanced fertilizer that has a formulation of 20-20-20, administered during the growing season, ideally once a month. Always follow the manufacturer's guidelines and avoid over-fertilizing as it can result in a build-up of salt in the soil.
Pruning
Pruning is essential to maintain a desirable size and shape of the plant. Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff responds well to pruning, and it's best done during the onset of spring. Remove the dead or diseased parts of the plant to prevent the spread of pests or disease. You can also control the shape by cutting off the new growth tips. Always use sanitized pruning tools to minimize the risk of infection.
Propagation of Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff
Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff, commonly known as uki or Hawaiian pepperweed, is a slow-growing plant that is only found in Hawaii. It is a rare shrub that is mostly propagated through vegetative means rather than seeds. The methods of propagation include:
1. Stem Cuttings
Stem cuttings can be taken from mature plants during the summer months. The cuttings should be approximately four inches long and should come from the new growth of the plant. The cuttings can then be planted in a potting mix that contains equal parts of peat and perlite. Cover the cuttings with a clear plastic bag and place them in a warm and bright location until they root.
2. Transplantation
Another method of propagation is through transplantation. This method involves digging up a portion of the parent plant and transplanting it to another location. This method works best if the parent plant has a well-established root system. When transplanting, it is important to disturb the roots as little as possible.
3. Air-layering
Air-layering is a method of propagation that can be used if the stem of the parent plant is too woody for stem cuttings. This method involves wounding the stem by removing a ring of bark and covering it with soil or sphagnum moss. The wound will stimulate the growth of new roots, which can be severed from the parent plant once they are well-established.
Propagation of Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff can be challenging, and it is recommended that these methods be done by experienced gardeners. However, propagating this rare and beautiful plant can help ensure its survival for future generations to enjoy.
Disease Management
Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff is susceptible to a number of diseases, including:
- Leaf spot
- Anthracnose
- Rust
- Root rot
To manage these diseases, it is important to practice good cultural practices. These practices include:
- Proper watering and drainage to avoid waterlogged soil
- Removing infected plant material and disposing of it properly
- Avoiding overhead irrigation, which can spread diseases
- Applying a fungicide if necessary, following label instructions
Pest Management
Nototrichium sandwicense (Gray) Hbd. var. olokeleanum Sherff may also be susceptible to various pests, such as:
- Aphids
- Mealybugs
- Spider mites
To manage these pests, it is important to practice good cultural practices such as:
- Regularly inspecting plants for signs of infestation
- Washing plants with a strong stream of water
- Applying an insecticidal soap or oil if necessary, following label instructions
- Encouraging natural predators such as ladybugs or lacewings
