Draba lonchocarpa Rydb. var. exigua O.E. Schulz
Draba lonchocarpa Rydb. var. exigua O.E. Schulz is a species of flowering plant that belongs to the family Brassicaceae. It is commonly known as the Tumamoc Hill Whitlowgrass due to its occurrence on Tumamoc Hill in Tucson, Arizona.
Origin
The Draba lonchocarpa Rydb. var. exigua O.E. Schulz is native to the Southwestern United States and Northern Mexico. It is most commonly found in rocky soils throughout the Sonoran Desert and Great Basin regions of North America. It is adapted to grow in high elevation rocky areas, including canyons, slopes, and ridges.
Common Names
Draba lonchocarpa Rydb. var. exigua O.E. Schulz is commonly known by several other names including Tumamoc Whitlow-grass, Tumamoc Hill Draba, and Sticky Whitlowgrass.
Appearance
The plant is an annual herb, usually growing to a height of 5-15 cm. It has an unbranched stem with tiny, white or yellow flowers that bloom from March to May. The leaves are succulent and fleshy. The plant is identifiable by its yellow-green foliage that emits a pungent odor when crushed. Seed pods are linear and usually curved upwards, with a length of 10-22 mm.
Uses
Draba lonchocarpa Rydb. var. exigua O.E. Schulz is not commercially cultivated but is used in plant restoration projects to restore damaged desert ecosystems. It is a valuable species for its drought-tolerance abilities and the ability to survive in nutrient-poor soils. The plant may also have potential as a bioindicator of heavy metal contamination in the environment due to its ability to accumulate heavy metals in its tissues.
Light Requirements
Draba lonchocarpa Rydb. var. exigua O.E. Schulz is a plant that requires full sunlight to grow optimally. It needs at least 6 hours of direct sunlight exposure per day to ensure healthy growth and development. Insufficient light can result in stunted growth, poor flowering, and decreased vigor."
Temperature Requirements
This plant can tolerate extreme weather conditions, but it prefers a cool and moist environment to thrive. Draba lonchocarpa Rydb. var. exigua O.E. Schulz can withstand temperatures as low as -35°C during winter and as high as 30°C during summer. However, this plant grows best at moderate temperatures between 16°C - 22°C.
Soil Requirements
The plant Draba lonchocarpa Rydb. var. exigua O.E. Schulz prefers well-drained sandy soils with a slightly acidic pH (between 6.0-7.2). The soil should be nutrient-rich and moist but not water-logged. It can also tolerate dry soil conditions, but it's essential to water the plant regularly in such cases. To ensure sufficient growth, it's advisable to add organic matter such as compost, manure, or peat moss to the soil.
Cultivation
Draba lonchocarpa Rydb. var. exigua O.E. Schulz prefers to grow in moist to dry, well-drained soils in full sun to partial shade. The plant can tolerate a wide range of soils types, including gravelly, rocky, and sandy soils. It is well adapted to grow in high altitude regions where the summers are cool, and the winters are cold.
Watering Needs
Draba lonchocarpa Rydb. var. exigua O.E. Schulz requires regular watering during the growing season, especially when the topsoil is dry to the touch. Watering should be done early in the day, allowing enough time for the foliage to dry before nightfall. Overwatering should be avoided as it may cause root rot and other fungal diseases.
Fertilization
Draba lonchocarpa Rydb. var. exigua O.E. Schulz does not require frequent fertilization. A slow-release, balanced fertilizer can be applied during the early spring before the onset of the growing season. Over-fertilization should be avoided as it may encourage lush foliage growth at the expense of the plant's flowers.
Pruning
Draba lonchocarpa Rydb. var. exigua O.E. Schulz does not require pruning except to remove any dead or damaged stems or spent flowers. Pruning should be done during the dormant season or after flowering. The plant can self-seed, and to prevent overcrowding, the seedlings can be thinned out or transplanted to other areas.
Propagation of Draba lonchocarpa Rydb. var. exigua O.E. Schulz
Draba lonchocarpa Rydb. var. exigua O.E. Schulz, commonly known as the wedge-scale draba, is a species of flowering plant in the Mustard family. It is a small alpine plant that grows in rocky soil and is native to the western United States and Canada. The plant is easily propagated by seeds, cuttings, or division.
Propagation by Seeds
The most common method of propagating Draba lonchocarpa is by seeds. The seeds can be collected from the mature plants and sown directly into the soil. The best time to collect the seeds is when the seed pods have turned brown and begun to split. The seeds should be sown directly into the soil in the fall before the winter season. Before sowing, the soil should be prepared by removing any large rocks and ensuring that it is loose and aerated. The seeds should then be covered lightly with soil and watered regularly. The seeds will usually germinate in the spring after the snow has melted.
Propagation by Cuttings
Draba lonchocarpa can also be propagated by cuttings. Cuttings should be taken in the early summer when the new growth is soft. The cuttings should be about 6 inches long and should be taken from the base of the plant. The cuttings should then be dipped in rooting hormone and planted in a well-draining soil mixture. The cuttings should be kept moist but not soggy, and should be placed in a cool area with filtered light. The cuttings will usually root in about four weeks and can be planted outside in the fall or the following spring.
Propagation by Division
Draba lonchocarpa can be propagated by division in the early spring or fall. The mature plant should be dug up and gently separated into smaller sections. Each section should contain a healthy root system and some green growth. The sections should then be planted in a well-draining soil mixture and kept moist but not soggy. The newly planted sections should be placed in a cool, shaded area for a few days to help them adjust to their new environment. The plants will usually establish themselves within a few weeks and can be moved outside in the fall or the following spring.
Disease Management
Draba lonchocarpa Rydb. var. exigua O.E. Schulz is generally a hardy plant, but like many other plants, it can fall prey to diseases, which can result in stunted growth, discoloration, and death. Here are some common diseases that may affect the plant and ways to manage them:
Powdery Mildew
Powdery mildew is a fungal disease that can affect the leaves of the plant, causing them to become distorted and discolored. To prevent this disease, avoid crowding your plants and ensure proper air circulation. If you notice that your plant has been infected with powdery mildew, remove the affected leaves and apply a fungicide to the plant.
Blackleg
Blackleg is another fungal disease that can infect the stem of the plant, causing it to become soft and discolored. To prevent this disease, ensure that your plant is growing in fertile, well-draining soil. Additionally, avoid injuring the stem of the plant while planting or weeding. If your plant is infected with blackleg, remove and destroy the affected plant tissue.
Pest Management
Another issue that can affect the growth and development of Draba lonchocarpa Rydb. var. exigua O.E. Schulz is pest infestations. Here are some common pests that may affect the plant and ways to manage them:
Aphids
Aphids are a common pest that can suck the sap from the leaves, stunting the growth of the plant. If you notice that your plant has been infested with aphids, spray the plant with soapy water or a commercial insecticide specifically designed for aphids.
Spider Mites
Spider mites are another pest that can affect the plant, causing the leaves to become yellow and stippled. To manage spider mite infestations, spray the plant with water to dislodge the mites and apply a pesticide that is specifically designed to control spider mites.
