Chamaecyparis thyoides, the Atlantic White Cypress, is an evergreen coniferous tree in the genus Chamaecyparis, of the cypress family Cupressaceae. It is also known as "Atlantic White Cedar" (confusing because it is a cypress, not a cedar). It is native to the Atlantic coast of North America from Maine south to Georgia, with a disjunct population on the Mexican Gulf coast from Florida to Mississippi.

It is a small tree, reaching 15-25 m tall, with feathery foliage in moderately flattened sprays, green to glaucous blue-green in colour. The leaves are scale-like, 2-4 mm long, and produced on somewhat flattened shoots. The cones are globose, 4-9 mm diameter, with 6-10 scales.

There are two geographically isolated subspecies, treated by some botanists as distinct species, by others at just varietal rank:

• Chamaecyparis thyoides subsp. thyoides (Atlantic White Cypress). Atlantic coast. Leaves and cones usually glaucous blue-green; cones 4-7 mm long. Conservation status: Secure
• Chamaecyparis thyoides subsp. henryae (Gulf White Cypress). Mexican Gulf coast. Leaves and cones always green, not glaucous; cones 6-9 mm long.

Cultivation and uses

Chamaecyparis thyoides is of some importance in horticulture, with several named cultivars of varying crown shape, growth rates and foliage colour having been selected for garden planting.