Origin and Common Names
Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz, also commonly known as smooth deervetch, is a herbaceous perennial plant species that belongs to the family Fabaceae. It is native to western North America, including British Columbia, Montana, Idaho, Oregon, Washington, and California.
General Appearance
The smooth deervetch plant grows up to 1 meter (3.3 feet) tall and has smooth and slender stems that are green or tinged with purple. Its leaves are pinnately compound, with 7 to 17 leaflets that are narrow and elongated. The flowers are papilionaceous and bloom from late spring to early summer. They are typically blue to purple in color, and occasionally pink or white. The plant produces a narrow to oblong pod that contains up to 10 small brown seeds.
Uses
The smooth deervetch plant has several uses, both for humans and animals. Native American tribes have used it as a medicinal plant to treat various ailments, such as stomach aches, fever, and rheumatism. The plant is also used as a forage plant for cattle, sheep, and goats, as it is highly nutritious and palatable. Additionally, the plant is used for erosion control and soil stabilization, as it has a deep root system that can help prevent soil erosion.
Growth Conditions for Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz
Light Requirements: Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz thrives in full sun to partial shade. It requires a minimum of six hours of direct sun per day to grow and develop properly. Plants that do not get enough sunlight tend to become weak, leggy, and prone to disease.
Temperature Requirements: The optimal temperature range for Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz growth is between 18°C and 30°C. In temperatures below this, the plant growth slows down; while in temperatures above this, the plant growth becomes stressed. It is best to plant seeds in the early spring, as the temperatures start to warm up.
Soil Requirements: The soil for Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz should be well-draining, slightly acidic to neutral, and rich in organic matter. A pH level of 6 to 7 is optimal for proper growth and development. The plant prefers sandy soil over heavy clay soils, as these retain too much moisture, which can lead to root rot. Additionally, the soil should be moist but not overly wet, as waterlogged soils can stunt growth and cause the plant to die due to root rot.
Fertilization: Fertilizer application is essential for this plant because it requires essential nutrients to grow and develop properly. A balanced fertilizer applied before planting and after fertilizing is necessary throughout the growing season. Once the plant has matured, a slow-release fertilizer applied once per month is sufficient to provide the plant's needed nutrients.
Cultivation Methods
Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz is a plant that requires full sun and well-draining, sandy soil. It is best to sow the seeds directly in the ground rather than transplanting seedlings. The seeds should be sown in the early spring and covered with a light amount of soil. As the plant grows, it should be thinned out to allow for proper spacing.Watering Needs
The plant should be watered regularly, especially during dry spells. It is best to water it deeply once a week rather than frequent shallow watering. This will encourage deeper root growth and a healthier plant. However, care should be taken not to overwater, as this can lead to root rot.Fertilization
Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz is a low-maintenance plant that does not require much fertilizer. However, if the soil is poor, a slow-release fertilizer can be applied during the growing season. It is important to follow the manufacturer's instructions and not to over-fertilize, as this can harm the plant.Pruning
Pruning is not necessary for Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz. However, if the plant becomes unruly or the stems start to bend, it may be necessary to pinch back the tips of the stems. This will encourage the plant to bush out and create a more attractive form. Deadheading spent flowers can also encourage more blooms.Propagation of Lotus Purshianus F.E. & E.G. Clem. var. Glaber (Nutt.) Munz
Lotus purshianus is a native plant to California, Arizona, and Nevada. It is a hardy perennial shrub that grows compactly in sandy or gravelly soils. The plant has a deep taproot that makes transplanting a bit difficult, so propagation is the best way to propagate this species. There are two primary methods of propagation for Lotus purshianus: seed and stem cutting.
Propagation by Seed
The first step in propagating Lotus purshianus by seed is to collect mature seed pods after the plant has finished blooming. The pods will dry out and turn brown on the plant when they are ready to be harvested. Once harvested, break open the pods and remove the small seeds. Soaking the seeds in warm water for 24 hours helps to increase the germination rate. After soaking, seeds can then be planted in seed trays or directly in the ground. Keep the soil moist but not waterlogged and provide plenty of sun. Germination usually occurs within 14 to 28 days.
Propagation by Stem Cutting
The other method of propagating Lotus purshianus is through stem cutting. Cuttings should be taken in late spring or early summer when the new growth begins to emerge. Cut leafy sections of the plant containing two to three nodes. Remove the leaves from the lower third of the stem and dip the cut end in rooting hormone. Place the stem cuttings in a well-draining potting mix. Cover the cuttings with plastic, and place them in a shaded area where they can receive indirect sunlight. Keeping the soil consistently moist and warm will encourage root development. Roots should begin to develop within 4 to 8 weeks.
Disease Management
Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz is a relatively disease-resistant plant. However, it is still vulnerable to a few diseases that may affect its overall health.
One of the most common fungal diseases affecting this plant is the powdery mildew caused by Erysiphe polygoni. The disease appears as a white powdery coating on the leaves, stems, and flowers, leading to leaf yellowing and dropping. Management of this disease requires fungicide applications early in the growing season.
Anthracnose, caused by the Colletotrichum gloeosporioides fungus, is another disease that may affect this plant's health. It results in the formation of black, sunken areas on the leaves, flowers, and fruits. The best management approach here is to maintain proper garden sanitation, control insect infestations, and use proper irrigation practices to reduce leaf wetness.
Pest Management
Apart from diseases, Lotus purshianus F.E. & E.G. Clem. var. glaber (Nutt.) Munz is also susceptible to pest infestations that may cause damage to the plant, reducing its overall vigor.
Spider mites and aphids are common pests that may attack this plant. They feed on the plant's sap, causing leaf curling, discoloration, and death. To manage this, growers can deploy predatory insects like ladybugs or lacewings, regularly monitor plants for early detection, and use horticultural oils to suffocate the pests.
Caterpillars, such as the cabbage looper, may also feed on the plant's leaves, resulting in irregularly shaped holes. In severe cases, the plant's defoliations may occur, leading to significant damage. Using Bacillus thuringiensis var. kurstaki (Btk) and neem-based insecticides can help control caterpillar infestations.
