Pinus roxburghii Seeds | Chir Pine
LATIN NAME: Pinus roxburghii
COMMON NAME: Chir Pine, Longleaf Indian Pine
Plant Profile
A chir pine announces itself from a distance by the movement of its crown. The needles grow in bundles of three, up to about thirty centimetres long, and they hang from the branch tips rather than bristling outward, so the tree looks combed and perpetually wet. No other pine of the Indian subcontinent carries needles of that length.
The cones are heavy and hard, and they sit wedged between the branches at right angles to the shoot, often several together in a whorl. Because they are held so tightly and open slowly, a chir pine often carries cones of two seasons at once, and fallen cones litter the forest floor for months. Households have long used them as kindling, since the resinous scales catch a flame readily.
The species was long known as Pinus longifolia, a name that could not be maintained under the rules of botanical nomenclature. Charles Sprague Sargent renamed it for William Roxburgh, the Scottish surgeon and botanist whose work on Indian plants laid the foundation for later flora writing. The older name still appears in forestry literature and on old labels.
Chir pine dominates the subtropical belt of the Himalayan foothills, a band of forest sitting above the hot plains and below the broad-leaved oaks and rhododendrons. It grows on dry stony slopes and ridges, often on poor soil, and it is a light-demanding pioneer that regenerates best where the ground has been bared. Fire helps it: thick bark protects mature trunks, and the flames clear the competition.
The solid fraction left behind is rosin, a glassy mixture of diterpene resin acids in which abietic acid and its isomers predominate. Rosin goes into adhesives, printing inks, paper sizing and varnish, and it has been traded worldwide under the old naval stores heading since the era when pine forests supplied navies with pitch and tar.
Science & Biotechnology
The species supplies most of India’s gum oleoresin. Tapping begins with a blaze cut into the trunk and a pot fixed below it, and the resin runs down the channel and collects. Traditional tapping removes wood and shortens a tree’s working life; modern methods use a narrower cut and apply a paste containing ethephon, a compound that releases ethylene and prolongs the flow without wounding so much of the trunk.
The crude resin is distilled with steam to separate the volatile fraction from the solid one. The volatile fraction, turpentine, is dominated by alpha-pinene with beta-pinene and carene, and it has served as a solvent and as a feedstock for making camphor and synthetic aroma chemicals. Every stage of that process belongs to large-scale industry rather than to craft.
Uses & Benefits
The wood is resinous and durable but awkward to work because the resin gums saws, so it has gone mainly into boxes, crates, tea chests and construction timber. It burns hot and is a major domestic fuel, and charcoal made from it is used in smithing. The seeds are small and winged rather than edible; the pine nuts of the region come from other species.
Growing from Seed
The needle litter under a chir pine stand is deep and dry, and it burns. Ground fires sweep through the belt in most years, killing seedlings and young broadleaved trees while leaving the pines standing. Larvae of the moth genus Dendrolimus defoliate whole hillsides in outbreak years, and bark beetles follow drought. Together, fire and insects keep the chir belt open and pine-dominated.
Sow the winged seed in a deep pot of two parts coarse sand, one part loam and one part leaf mould, pressing it onto the surface and covering it with a few millimetres of grit. Give the pan full sun and free drainage, and keep it outdoors through winter in a cold frame, because the seed wants cold and damp rather than warmth. Water sparingly once the seedlings are up, since a wet closed pot rots pine roots.
Move the young pines into deep pots singly once their stems have stiffened, and keep them in full sun. Plant out when the trunks are as thick as a finger and the roots have filled the pot, spacing trees at least six metres apart, because a chir pine grows fast and carries a heavy crown. Stake against wind for the first seasons, keep weeds away from the root zone, and never cut the leader.
Our Take
Long-needled pines are their own small fraternity. Pinus wallichiana grows in the same Himalayan belt a little higher up and carries five needles in a bundle rather than three, while Pinus kesiya takes over further east and south. For edible nuts rather than timber, Pinus gerardiana is the species worth growing.
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