CONIFERS

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.

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.

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 22 in (55 cm) long. They have sturdy 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.