Family: Apocynaceae
Common name: Devil’s tree, Blackboard tree, Milkwood, Scholar tree, Milkwood tree, Indian pulai, Saptaparna, White cheesewood, Bitter bark, Dita bark
Blackboard tree is a tall, stately tree that can be grown in home gardens or in landscaped areas, providing shade and nesting place for birds; at the same time filling the place with fragrance. They originated from India and can be seen very commonly in gardens.
Tree characteristics
Blackboard or Devil’s tree can grow very tall, to a height of 30-40 meters with a strong, sturdy trunk that is greyish-brown in color.
Bark can be smooth when young, growing slightly fissured and cracked as the tree ages. The tree trunk has lenticels, or small openings that allow for exchange of gases.
The tree usually has a well-rounded, dense canopy in the shape of an umbrella, with an approximate spread of 10-15 meters. Blackboard trees take around 15-20 years to reach maturity.
Leaves are seen in large whorls of three to ten leaflets, each of them lance-shaped or elliptical, measuring about 15-25 cm in length and 4-8 cm in width. These leaves are dark green and glossy with smooth margins, growing very thickly along the stems.
Blackboard trees flower copiously during Aug-Sep, filling the tree with cream or pale yellow flowers that are fragrant. Each flower is 1.5 to 2.5 cm in diameter.
The fragrance is like that of the flowers of Indian cork tree or Millingtonia hortensis, sweet and heady. Since they bloom in plenty, pollinators like bees, butterflies, and insects are drawn in hundreds to the tree.
Fruits of the Blackboard tree are very unique; slender, elongated pods that hang down like streamers from the tree. They are 10-15 cm long, almost cylindrical in cross-section, containing several flat, winged seeds that are dispersed by the wind.
These seedpods are initially green, gradually turning brown on maturity, before they split open to release the seeds.
Gardening Tips
Blackboard trees need good sunlight and well-drained soil. Before planting, make sure that the tree has enough space to grow, lest its growth be stunted by other vegetation around it.
These trees need watering only when they are small. Once established in the soil, the roots can go very deep in search of water, sustaining the tree. Pruning can be done when the tree is small, to maintain a well-rounded crown.
Spraying neem oil or insecticides can also keep the tree pest-free when they are small. Blackboard trees live for over 100 years, sustaining life and providing beauty to its surroundings.
Uses of Blackboard tree
Blackboard trees are usually grown as ornamentals tree, or for shade in gardens. They can also add beauty and majesty to large, landscaped areas like parks and public spaces, providing abundant shade, and shelter for birds and small animals.
In addition to this, the Blackboard trees have medicinal uses in the treatment of ulcers, dropsy, beri beri, wounds, skin diseases, fever, stomach pain, intestinal worms, dysentery, irregular menstruation, malaria, and rheumatism.
The bark of the Blackboard tree is used for producing dyes, and it also provides reasonably strong fiber. The wood is not very strong or durable; and so they are used for making carvings, pattern, mouldings etc. They are more suited for pulp and paper manufacturing.
Propagation
Propagation is through seeds and stem cuttings. Seeds collected from mature, healthy seedpods should be soaked in water for about 24 hours to help speed up germination. Plant them in moist, well-drained soil and they should germinate in 2-4 weeks.
Semi-hardwood cuttings taken from healthy trees, can be planted in a well-draining potting mix, after dipping the end in rooting hormone.
Photographed at: Olde Bangalore Resort
