Overview
Orobanche cooperi (Gray) Heller, also known as Cooper's broomrape, is a plant species in the Orobanchaceae family. This parasitic plant grows in the western United States and is known for its unique appearance and its parasitic relationship with other plants. It lacks chlorophyll and obtains its nutrients from the roots of other plants.
Common Names
Cooper's broomrape is the most commonly used name for Orobanche cooperi. However, it is also known by other names such as Cooper's broom-rape, Cooper's cancer-root, and purplish broomrape.
Appearance
Orobanche cooperi has a unique appearance that makes it easily identifiable. It has purple to pinkish flowers that bloom from May to August. The flowers grow to be about 1-2 cm long and have a tubular shape. The stems are fairly stout and grow to be 20-45 cm tall. It lacks leaves and does not have chlorophyll, which gives it a yellow to light brown color.
Uses
While Orobanche cooperi does not have any known medicinal or commercial uses, it is known to be important in its ecosystem as a parasitic plant. It obtains its nutrients from the roots of other plants, which can help regulate the growth of some species in an ecosystem. Orobanche cooperi has also been observed to provide habitat for some insects, such as ants and beetles.
Light Requirements
Orobanche cooperi is an obligate parasite and does not require light for photosynthesis like other plants. Instead, it extracts its nutrients from the roots of host plants. Therefore, Orobanche cooperi has no specific light requirements as it grows entirely underground and does not produce chlorophyll.
Temperature Requirements
Orobanche cooperi is generally found in semi-arid to arid regions with hot summers and mild winters. It can tolerate temperatures ranging from 10°C to 35°C (50°F to 95°F). Orobanche cooperi can grow in areas with periodic droughts and temperatures higher than 35°C, but the host plants upon which it relies may not survive under such conditions.
Soil Requirements
Orobanche cooperi is a root parasite, and its growth and development depend entirely on its host plants, which can vary depending on location. The host plants of Orobanche cooperi usually grow in sandy to rocky soils with low fertility. The roots of Orobanche cooperi penetrate the host plant's roots to extract water, minerals, and other essential nutrients needed for its growth and development. As Orobanche cooperi does not have its own chlorophyll to produce food from sunlight, it does not require any specific soil nutrient content to survive.
Cultivation
Orobanche cooperi, also known as Cooper's broomrape, is a parasitic plant that requires a host to grow. It's important to select a suitable host plant that can sustain the broomrape. The plant can be grown from seeds or by transplanting young plants onto the host plant. It's recommended to plant the broomrape in the fall or spring to ensure proper growth.
Watering Needs
Since Orobanche cooperi is a parasitic plant, it usually does not require much watering. In fact, excess watering can lead to root rot and even death. It's important to let the host plant's roots grow strong before introducing the broomrape. However, during the dry season, watering the host plant may help the broomrape establish a better connection and improve nutrient uptake.
Fertilization
Orobanche cooperi derives most of its nutrients from the host plant, but it can benefit from occasional fertilization. It's important not to over-fertilize, as this could lead to excessive growth of the host plant and make it difficult for the broomrape to obtain enough nutrients. Use a balanced fertilizer and apply it sparingly to avoid any potential issues.
Pruning
There is no need to prune Orobanche cooperi, as it is a parasitic plant that grows on the host plant. However, it's important to monitor the host plant's growth and health, ensuring it stays healthy enough to support the broomrape. Remove any dead or diseased parts of the host plant promptly to avoid harming the broomrape.
Propagation of Orobanche cooperi
Orobanche cooperi, commonly known as Cooper's broomrape, is a parasitic plant that relies on a host plant for its survival. Due to its parasitic nature, there are certain challenges in propagating this plant. However, there are a few methods that can be used successfully for propagation:
Seeds
Seeds are the most common method of propagation for Orobanche cooperi. The plant produces tiny seeds that can be collected once they have ripened. They can be collected by placing a paper bag over the flower head after the petals have fallen off. The seeds can then be stored in a cool, dry place until the following planting season. Before planting, it is recommended to scarify the seeds to help break down the seed coat and increase the rate of germination.
Division
Another method of propagation for Orobanche cooperi is by division. This method involves separating the plant into smaller parts or sections and replanting them. However, as the plant is parasitic, dividing it may result in the death of the plant. Moreover, it might not be practical in the case of Orobanche cooperi because of its low-growing, ground-hugging habit.
Transplanting
Transplanting is a less commonly used method of propagation for Orobanche cooperi. This method involves removing a small portion of a mature plant and replanting it elsewhere. However, because the plant is parasitic, there are certain difficulties associated with transplanting it. Unless the transplanting is done carefully and correctly, the plant may not thrive or even survive in its new environment.
Overall, seeds are the best and most reliable method of propagating Orobanche cooperi. While division and transplanting may be possible, they are not typically recommended due to the plant's parasitic nature. If you are interested in cultivating this plant, obtaining seeds from a reputable source is likely the easiest and most successful way to get started.
Disease Management:
Orobanche cooperi is generally a healthy plant that is not prone to many diseases. However, there are a few diseases that can affect the plant:
- Root rots: This is caused by soil-dwelling fungi that attack the roots of the plant. Avoid overwatering and ensure proper drainage to prevent root rot. Remove and discard affected plants and avoid planting anything in the same spot for at least a year.
- Leaf spot: This is caused by a fungal pathogen that causes circular brown spots on the leaves of the plant. Remove and dispose of affected leaves and avoid overhead watering.
- Powdery mildew: This is a fungal infection that causes a white powdery coating on the leaves and stems of the plant. Remove infected leaves and increase air circulation around the plant to prevent powdery mildew.
Pest Management:
Although Orobanche cooperi is generally resistant to pests, there are a few pests that may attack the plant:
- Aphids: These are small, soft-bodied insects that suck sap from the plant and can cause distorted growth and yellowing of leaves. Spray the plant with a strong stream of water or use insecticidal soap.
- Spider mites: These are tiny pests that suck sap from the plant, causing foliage to yellow and die. Increase humidity and spray the plant with a strong stream of water to control spider mites.
- Thrips: Thrips damage the leaves of Orobanche cooperi by sucking sap from them. Use a systemic insecticide to control thrips on this plant.
