Nature^91
HOW DO CONIFERS PRODUCE SEEDS?
Conifers have male and female cones. The male cones
release pollen grains (male sex cells), which are blown
by the wind. If pollen lands on the female cones, it
fertilizes the female egg cells. The fertilized eggs develop
into seeds. After one or two years, when the seeds have
matured, the female cone opens up. It drops winged
seeds, which germinate wherever they land if
conditions are favourable.WHY DO SOME CONIFERS
HAVE NEEDLE-SHAPED LEAVES?
Leaves shaped like needles help conifers survive in
cold, harsh climates. The leaves are tough and coated
with a waxy outer coat, or cuticle. The narrow shape,
toughness, and cuticles all help the leaves withstand
high winds and extreme temperatures. They also
reduce water loss.DO OTHER PLANTS HAVE CONES?
A group of plants called cycads have large
seed-producing cones that can grow to more
than 55 cm (22 in) long. They have stout trunks
topped by long, divided leaves, and look more like
palm trees than conifers. Cycads grow in tropical
and subtropical regions. They are descended
from a group of plants that flourished 250
million years ago. Today, there are 140
species of cycads.1 PINE FOREST
The branches of pines and many other conifers slope downwards.
This helps winter snows to slide off, preventing damage to the tree.SCOTS PINE 3
Pine trees, like most conifers, are evergreen and keep
their leaves throughout the year. The long, spiky
needles stay on the tree for at least two years.PINE SEEDSFemale cones
are woody, and
open to release
their seedsCONIFERS
Trees and shrubs whose seeds develop in woody
cones are called conifers. The 550 species include
pines, firs, and cedars. Conifers form dense
forests in colder, northern regions. Most keep
their leaves all year long.1 STONE PINE CONE
Seeds mature inside the female
cone, protected by its scales.
In warm, dry conditions,
the cone opens to
release its seeds.Male cones are
soft, and drop off
after shedding
pollenFIND OUT MORE. Climate 62–63 • Habitats 82–84 • Plants 88–89 • Trees 94–95