Description of Astragalus triquetrus Gray
Astragalus triquetrus Gray, commonly known as Three-awned milkvetch, is a herbaceous perennial plant of the legume family Fabaceae. This plant is native to North America and is found in many areas including the western United States, Mexico, and Canada.
Common Names
The Astragalus triquetrus Gray is commonly known as Three-awned milkvetch, Three-awned milk-vetch, Three-tip milkvetch, and Three-tip vetch.
General Appearance
The Three-awned milkvetch is a low-growing plant that typically grows up to 30 cm tall and 30 cm wide. It has a branching stem with long, narrow, trifoliate leaves. The leaves are generally green with a silvery sheen and have a slightly hairy surface.
The plant produces a pink to purple colored flower that usually appears from May to July. The flower is shaped like a pea and has two small wings and a curved, pointed, keeled lower petal. The fruit is a small, slightly curved pod that contains seeds.
Uses
The Three-awned milkvetch has been traditionally used by Native Americans for various medicinal purposes. The plant was believed to have properties that could help with ailments such as fever, coughs, and digestive issues.
In addition to its medicinal value, the Three-awned milkvetch is also used for erosion control and as a forage for livestock. The seeds produced by the plant are also used as a source of food for wildlife.
Light Requirements
Astragalus triquetrus Gray requires full sun exposure and grows best in open, sunny areas. It is not tolerant of shady conditions and may not survive in areas with limited sun exposure.
Temperature Preferences
Generally, Astragalus triquetrus Gray prefers cool to moderate temperatures and can tolerate temperature fluctuations. It grows well in areas with an average temperature range of 5-30°C (41-86°F). However, it may not survive in areas with extreme temperatures, such as those found in deserts.
Soil Requirements
The plant grows in well-drained soil that is sandy, rocky, or gravelly. It can tolerate soils with high alkalinity or acidity, but it prefers soils with a pH of 7.0-8.5. The soil should be rich in minerals, particularly phosphorus and nitrogen, to support growth. Adequate soil moisture and good drainage are also crucial for the plant's development.
Cultivation
Astragalus triquetrus Gray, commonly known as Three-horned Milkvetch, is a hardy perennial legume native to the western United States. It grows well in USDA hardiness zones 4-10 in full sun to partial shade.
The plant prefers well-drained soils and is tolerant of dry conditions once established. It can also grow in rocky soils and is often found on steep slopes and ridges in its native range.
Propagation can be done from seeds, which can be sown in the spring or fall. It is also possible to propagate the plant through division in the fall.
Watering Needs
As an arid-land plant, Astragalus triquetrus does not require frequent watering. However, during the first growing season, it is important to ensure the plant receives enough water to establish its root system. Afterward, it can tolerate drought conditions, and regular watering is unnecessary unless there are extended periods of hot and dry weather.
Fertilization
Astragalus triquetrus is a legume and is capable of fixing nitrogen from the air through its symbiotic relationship with rhizobia. Therefore, it does not require additional fertilization. In fact, fertilizing with nitrogen can negatively affect the plant's ability to fix atmospheric nitrogen.
Pruning
Pruning is unnecessary for Astragalus triquetrus, but removing dead stems and flowers can promote new growth and improve the plant's appearance. It is important to avoid pruning the plant heavily in the fall as it can reduce winter hardiness.
Propagation of Astragalus triquetrus Gray
Astragalus triquetrus Gray, also known as Three-angled milkvetch, is a herbaceous plant native to North America. It can be propagated by seed or vegetatively through stem cuttings.
Propagation by Seed
Propagation by seed is the most common method for Astragalus triquetrus Gray. Seeds should be sown in the fall or early spring in a well-draining soil mix, lightly covered with soil and kept moist. Germination usually occurs within 2-3 weeks. The seedlings can be transplanted to individual pots once they are large enough to handle and can be planted in their permanent location in the garden after 1-2 years.
Vegetative Propagation
Astragalus triquetrus Gray can also be propagated vegetatively through stem cuttings. Cuttings should be taken in early summer from the current year's growth and should be 4-6 inches long. Remove the lower leaves and dip the cut end in a rooting hormone. Stick the cuttings in a well-draining soil mix and keep the soil moist. The cuttings should root in 2-3 weeks and can be transplanted to individual pots. Once they have developed a good root system, they can be planted in their permanent location in the garden.
Disease Management
Astragalus triquetrus Gray is relatively resistant to disease. However, it can still be affected by some diseases that can lead to significant damage if not addressed.
Fusarium Wilt: This fungal disease can attack the roots and stem of the plant and cause it to wilt. It is a severe disease that can quickly spread and cause death. To manage this disease, promptly remove infected plants and destroy them to avoid the spread of the disease to other plants.
Crown Rot: This is another fungal disease that mainly affects the stem base, crown, and roots. The infected plant shows symptoms of discoloration, wilting, and root decay leading to plant death. To manage this disease, avoid overwatering, and properly space the plants to encourage good air circulation. Remove and destroy all infected plants to avoid the spread of the disease.
Leaf Spot: Leaf spot is a bacterial and fungal disease that presents as lesions on the leaves. The leaves show yellow, gray, or brown spots, which may drop off and cause defoliation. To manage this disease, remove and destroy all infected leaves to prevent the spread of the disease. Ensure the plant has good air circulation and avoid overhead watering to reduce moisture on the leaves.
Pest Management
Astragalus triquetrus Gray is susceptible to a few pests that can cause substantial damage if not addressed promptly. Below are some of the common pests that can affect the plant:
Aphids: These are small soft-bodied insects that feed on the leaves and stems of the plant. They usually form colonies that can cause significant damage to the plant. To manage them, spray the plant with water to dislodge them or use insecticidal soap if necessary.
Mites: Mites are tiny spider-like pests that suck plant sap from the leaves, causing damage and stunted growth. They usually hide on the underside of the leaves. To manage them, ensure the plants have good air circulation and remove any infected leaves promptly. Use insecticidal soap or neem oil to manage heavier infestations.
Thrips: Thrips damage the plant by sucking sap, which can cause distorted growth, curling leaves, and silvering or bronzing of the leaves. To manage them, regularly spray the plant with water and remove any infected plant matter. Use insecticidal soap or neem oil to manage heavier infestations.
It is essential to note that while chemical control is effective in managing pests and diseases, it can harm beneficial insects and pollinators. Therefore, consider using cultural methods and biological control options as alternatives to minimize harm to the environment.
