Overview
Pycreus polystachyos, also known as Rottboellia polystachya, is a species of perennial grass in the family Poaceae. It is native to tropical and subtropical regions of Africa, Asia, and Australia. The plant has multiple common names, including Buttongrass, Alarm grass, and Blady grass.
Appearance
Pycreus polystachyos can grow up to 3 feet in height and has long, slender leaves that taper to a point. The inflorescence consists of multiple spikelets that are arranged in dense clusters. The spikelets are small and have a button-like appearance, which is where the common name "Buttongrass" comes from. The plant's flowers are usually green or brown in color.
Uses
Pycreus polystachyos has several practical uses. In Africa, the plant is used as a medicinal herb to treat a variety of ailments such as diarrhea, colic, and rheumatism. Additionally, the plant's leaves are used as a natural insecticide. The grass is also used as forage for livestock and is planted in erosion-prone areas to help prevent soil erosion.
Interestingly, the plant has been used in some cultures to determine the onset of rainy season. When the plant senses an increase in humidity, its leaves will droop down until they are nearly touching the ground in a phenomenon known as "Alarm grass."
Cultivation
Pycreus polystachyos can be grown in both dry and wet conditions, and it is tolerant of a range of soil types. The plant can be propagated by seed or by dividing clumps in early spring. After planting, the plant should be watered regularly until it is established. Once established, it should be watered only during dry spells. The plant requires full sunlight and can be grown in USDA zones 9 through 12.
Light Requirements
Pycreus polystachyos (Rottb.) Beauv. requires full sunlight exposure to thrive. The plant cannot grow adequately under shaded conditions or limited light. Generally, the plant grows well in open areas with abundant light penetration.
Temperature Requirements
The plant can tolerate a wide range of temperature conditions. However, it does best when grown in areas with temperatures ranging between 20°C and 30°C. The plant can withstand high-temperature conditions of up to 40°C but requires adequate moisture availability. Furthermore, the plant can survive frost conditions for a short period but will require protection to continue growing healthily.
Soil Requirements
Pycreus polystachyos (Rottb.) Beauv. grows well in well-drained soils with high organic matter. The soils should have a pH range of between 5 and 8.5. Nevertheless, the plant can tolerate soil salinity, acidity, and alkalinity to a certain extent. The plant can grow in a variety of soils, including sandy, clay, and loamy soils, as long as the conditions are well-drained and not waterlogged.
Cultivation Methods
Pycreus polystachyos can be grown indoors or outdoors. It prefers full sun exposure but can tolerate partial shade. This plant requires well-draining soil and can thrive even in poor soil conditions. The ideal temperature for its growth is between 21°C to 32°C. The plant can be propagated through seeds or division of rhizomes.
Watering Needs
Pycreus polystachyos requires consistent watering in dry conditions. It can tolerate brief periods of drought but should be watered enough to keep the soil moist. Watering should be done when the top inch of soil feels dry to the touch. Over-watering can cause root rot and other fungal diseases.
Fertilization
Pycreus polystachyos rarely requires fertilization. It can do well with a balanced all-purpose fertilizer applied monthly during the growing season. Over-fertilization can cause rapid growth, leading to leggy plants that are more susceptible to pests and diseases.
Pruning
Pycreus polystachyos does not necessarily require pruning, but it can be done to control its spread and maintain its shape. If necessary, pruning should be done in spring or fall. Remove any yellow or dead leaves as well as any old flowers or seed heads. The plant can be cut back to the ground to control its size or to rejuvenate it.
Propagation methods for Pycreus polystachyos (Rottb.) Beauv.
Pycreus polystachyos (Rottb.) Beauv. is a perennial plant that can be propagated by both sexual and asexual means.
Propagation through seeds
Seeds of Pycreus polystachyos can be collected from the matured spikes. The seeds should be sown in sterilized soil and kept under optimum conditions of temperature and moisture. Germination usually takes 2-3 weeks.
The seedlings can be transplanted to individual pots when they are large enough to handle without damaging the roots. Once the plants reach a certain height, they can be transplanted to their permanent location in the garden or field.
Vegetative propagation
Pycreus polystachyos can also be propagated vegetatively by dividing the rhizomes. The rhizomes should be dug up and carefully separated with a sharp knife. Each division should have at least one healthy shoot and root system.
The divided rhizomes can be planted in individual pots or directly into the garden or field. It is important to keep the soil moist until new growth appears.
Another vegetative propagation method that can be used is stem cuttings. Select healthy stems and cut them into 5-7 cm lengths. Remove the lower leaves and dip the cut end in rooting hormone.
Stick the cuttings into moist, sterile soil and cover them with a plastic bag to maintain high humidity. Place them in a warm and bright location, and wait for root development. Once the cuttings have rooted, they can be transplanted to individual pots or directly into the garden or field.
Disease Management
Pycreus polystachyos is relatively resistant to diseases. However, several foliar diseases can affect this plant. The most common ones are:
- Leaf spot: This fungal disease usually appears as small brown spots on the leaves. To manage it, remove all infected leaves and control humidity around the plant.
- Powdery mildew: It is characterized by white powder-like spots on the leaves and stems. To manage it, spray the plant with a mixture of water and neem oil or insecticidal soap.
- Bacterial blight: This disease causes yellowing and wilting of leaves. To manage it, remove infected plant parts and apply copper-based fungicides.
Pest Management
Pycreus polystachyos is susceptible to several pests, including:
- Aphids: They are small green insects that suck sap from the plant, causing stunted growth and yellowing of leaves. To manage them, spray the plant with a mixture of water and insecticidal soap.
- Caterpillars: They feed on the leaves, causing large holes. To manage them, physically remove them and spray the plant with Bacillus thuringiensis.
- Spider mites: They are tiny and can cause yellowing and curling of leaves. To manage them, spray the plant with a mixture of water and insecticidal soap.
It is essential to monitor the plant periodically for signs of diseases and pests and to take appropriate control measures before the situation gets out of hand.
