They are evergreen trees or large shrubs. The leaves are scale-like, arranged in opposite decussate pairs, and persist for three to five years. On young plants up to two years old, the leaves are needle-like. The cones are long, globose or ovoid with four to 14 scales arranged in opposite decussate pairs; they are mature in 18-24 months from pollination. The seeds are small, 4-7 mm long, with two narrow wings, one along each side of the seed.
Many of the species are adapted to fire, holding their seeds for many years in closed cones until the parent trees are killed by a fire; the seeds are then released to colonise the bare, burnt ground. In other species, the cones open at maturity to release the seeds.
The fast-growing hybrid Leyland cypress, often found in gardens, draws one of its parents from this genus (Monterey cypress C. macrocarpa).
Cypress trees are not recommended due to their fire prone nature. Consider removing cypress trees within 100' of structures or 15' of roadways. If a tree must be maintained in the defensible space zone (within 100' of structures), extreme care should be taken to reduce the associated wildfire hazard.
Remove all limbs within 10' of the ground, or 1/3 the height of the tree if less than 30' tall
Remove all dead wood and twiggy growth regularly
Provide canopy separation so that no limbs touch nearby trees or plants
Remove all "ladder fuels," shrubs, and immature trees growing below
Remove fallen needles and detritus regularly
Remove any needles or limbs which fall on the roofs of nearby buildings, and repeat regularly during fire-season