Dhak or palas (Butea frondosais), is a medium-sized deciduous tree. Some botanists call it Butea monosperma. The family is Leguminosae-Papilioneae. This tree is also called 'Flame of the Forest' and Bastard Teak. It grows throughout Haryana, rest of the Indian subcontinent, especially in Indo-Gangetic plains, from 150 m to 1000 m. It is quite happy in black cotton soil, and therefore quite common from Sri Lanka north-wards i.e. the Indian Peninsula, especially the Deccan Plateau.
The bole of Dhak is twisted and gnarled and the branching too follows no particular pattern. It is slow growing and attains a height of about 5 to 8 m and diameter of about 20 to 40 cm when mature at the age of about 50 years or so. The bark of Dhak is fibrous and bluish gray to light brown in color. It exudes a kind of red juice when injured. That dries into a very useful gum.
The leaves of Dhak are compound. Each has three leaflets. The texture of the leaflets is fairly tough. These are coriascious with the surface glabrescent above and hairy silken beneath. The size varies from 15 cm to 20 cm by 10 cm x 15 cm. The shape is obliquely ovate and broadly elliptic. The leaves fall off by December and reappear during spring. When the tree is leafless, it bears flaming orange to red-colored flowers.
These flowers start appearing in February and stay on nearly up to the end of April. The size is nearly 2 to 4 cm in diameter. These tend to be densely crowded on leafless branches. The calyx i.e. the lower whorl of the flower tends to be darkish gray like the supporting branch itself. The upper parts are brick red. These give the plant so handsome a look despite it is leafless during spring season when entire terrain having Dhak trees wears a kind of exquisite orange and red hue. The flowers form a gorgeous canopy on the upper portion of the tree, giving the appearance of a flame from a distance.
The fruit of palas is a flat legume; a pod, nearly 15 cm long and 3 to 5 cm wide. Young pods have a lot of hair — a velvety cover. The mature pods hang down like peculiar legumes. The seeds are flat, from 25 to 40 mm long, 15 to 25 mm wide, and 1.5 to 2 mm thick. The seed-coat is reddish-brown in color, glossy, and wrinkled, and encloses two large, leafy, yellowish cotyledons. The hilum is conspicuous, and situated near the middle of the concave edge of the seed. The odor is faint, and the taste slightly acrid and bitter.
Dhak is a useful plant in many ways. Its leaves are essential for various religious rituals in Hindu homes. These are also used as cheap leaf plates and cups for rural feasts. In some parts of the country these are used for wrapping tobacco to make biddies. These are further used as packing material for parcels. The cattle also eat the Dhak foliage quite eagerly.
The bark of Dhak yields a kind of coarse and brown colored fiber, which is used for rough cordage. Butea gum is a dried astringent juice obtained from incisions in the stem of the tree. The juice exuded by the bark hardens in to brittle ruby colored gum beads. This gum is sanctioned to be used as a substitute for the kino gum. It finds use for caulking boats as well. The Dhak flowers yield an orange dye. A preparation of the same is used as an insecticide. The seeds are used in Ayurvedic and Unani medicine for treating a number of human maladies. The Dhak tree acts as a host for lac insect and is, therefore, useful in producing natural lac.
The wood of Dhak is greenish white in color. It is porous and soft in texture and has annual rings — though not very distinct. The wood is soft and weighs about 14 to 15 km per cubic foot. It generally perishes fast when used at sites open to vagaries of weather, but lasts much longer when used under water. It is therefore used for making well curbs and piles.
Dhak regenerates naturally and easily in mixed deciduous stands in temperate forests. Till some 30 years ago, many wastelands of Haryana were covered with Dhak trees. As research has not been done on its artificial regeneration, it is seldom planted artificially. It may also not be very profitable or even practical to raise its seedlings in nurseries. Even then, keeping in mind its various utilities, these trees coming up naturally in forest lands and elsewhere deserve to be given due protection.