Some pine cones stay sealed for years until a wildfire melts them open
Certain pines, including Pinus radiata, lock their cones shut with resin and hold their seeds for years. Only the heat of a forest fire melts the seal. The seeds then drop onto freshly burnt ground where rival plants have been cleared away, giving the next generation a head start that most trees never get.
Botanists call this delayed release serotiny, and the fire-triggered version pyriscence. Other pines take different routes. Most produce small winged seeds that ride the wind, while some have larger, almost wingless seeds spread by birds; the whitebark pine's seeds only come out when a bird breaks the cone apart. Female cones can take up to three years to mature after pollination, with fertilisation itself delayed a year, and may end up anywhere from 3 to 60 centimetres long.
Pines are conifers of the genus Pinus, spread widely across the Northern Hemisphere from boreal forest to the Mediterranean and dry tropical forests of south-east Asia and Central America. Most stand 15 to 45 metres tall. The record holder is a sugar pine in Yosemite National Park measuring 83.45 metres. Adult needles grow in bundles, usually of two to five, and last from a year and a half to 40 years depending on species. If an animal eats a shoot's growing tip, a bundle just below can sprout a replacement.
Their lifespans are extraordinary. Many live for centuries, and the Great Basin bristlecone pine outlasts them all: a tree nicknamed Methuselah in California's White Mountains is about 4,800 years old, making it one of the oldest living things on Earth. An even older one, near Wheeler Peak, was dated at 4,900 years, but it has since been cut down. Their branches, needles and cone scales spiral in Fibonacci ratios.
The word pine comes from Latin pinus, traced to an Indo-European root meaning resin, and until the 1800s English speakers commonly called them firs, a term that today belongs to a different genus. People have long put them to use: pine is among the most widely used timbers, pine nuts go into pesto, and retsina wine is flavoured with the resin.
Source: Pine
