Chamaecyparis is genus of conifers in the family Cupressaceae, native to eastern Asia and western and eastern North America. It is one of several genera within the Cupressaceae that have the common name cypress.
They are medium-sized to large evergreen trees growing to 20-70 m tall, with foliage in flat sprays. The leaves are of two types, needle-like juvenile leaves on young seedlings up to a year old, and scale-like adult leaves. The cones are globose to oval, with 8-14 scales arranged in opposite decussate pairs; each scale bears 2-4 small seeds.
There are five or six species, depending on taxonomic opinion:
- Formosan Cypress Chamaecyparis formosensis. Taiwan.
- Lawson's Cypress Chamaecyparis lawsoniana. Western North America.
- Hinoki Cypress Chamaecyparis obtusa. Japan.
- Sawara Cypress Chamaecyparis pisifera. Japan.
- Taiwan Cypress Chamaecyparis taiwanensis (syn. C. obtusa var. formosana). Taiwan.
- White Cypress Chamaecyparis thyoides. Eastern North America.
Another species which used to be included in this genus, as Chamaecyparis nootkatensis, has now been transferred on the basis of strong genetic and morphological evidence to the genus Cupressus as Cupressus nootkatensis (the name it was originally described under in 1824), or to a separate genus Callitropsis as Callitropsis nootkatensis.
Some of the species are sometimes wrongly called "cedars", a name that correctly refers to the genus Cedrus in the family Pinaceae.
Four species (C. lawsoniana, C. obtusa, C. pisifera, and C. thyoides) are of considerable importance as ornamental trees in horticulture; several hundred cultivars have been selected for various traits, including dwarf size, yellow, blue, silvery or variegated foliage, permanent retention of juvenile leaves, and thread-like shoots with reduced branching.
The wood is scented, and is highly valued, particularly in Japan, where it is used for temple construction.
Propagation is by seeds for the species, and cuttings or occasionally grafting, for named cultivars.
Pests and diseases
The species are used as food plants by the larvae of some Lepidoptera species including Juniper Pug Moth and Pine Beauty Moth. In some areas, cultivation is limited by Phytophthora root rot diseases, with C. lawsoniana being particularly susceptible to Phytophthora lateralis.
- Flora of North America: Chamaecyparis
- Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4.