Callitris
Encyclopedia
Callitris is a genus of coniferous tree
s in the Cupressaceae
(cypress family). There are 15 species in the genus, of which 13 are native to Australia
and the other two (C. neocaledonica, C. sulcata) native to New Caledonia
. Traditionally the most widely used common name is cypress-pine, a name shared by the closely related genus Actinostrobus
. However, this is inaccurate as these are just cypress and in no way pines, and they are increasingly being called cypress.
They are small to medium-sized tree
s or large shrub
s, reaching 5-25 m tall (to 40 m in C. macleayana). The leaves
are evergreen
and scale-like, except young seedlings, where they are needle-like; in C. macleayana, needle-like leaves are found mixed with scale leaves throughout the tree's life. The scales are arranged in six rows along the twigs, in alternating whorls of three (often in whorls of four in C. macleayana).
The male cones
are small, 3-6 mm long, and are located at the tips of the twigs. The female cones start out similarly inconspicuous, maturing in 18-20 months to 1-3 cm long and wide, globular to ovoid (acute in C. macleayana), with six overlapping, thick, woody scales, arranged in two whorls of three (often 8 scales in C. macleayana). The cones remain closed on the trees for many years, opening only after being scorched by a bushfire; this then releases the seed
s to grow on the newly cleared burnt ground.
The genus is divided into two sections, with the atypical C. macleayana in sect. Octoclinis, and all the other species in sect. Callitris. Some botanists treat C. macleayana in a separate genus, as Octoclinis macleayana. C. macleayana is also distinct in occurring in rainforest
on the east coast of Australia; the other species all grow on dry sites.
The closest relatives of Callitris are Actinostrobus
from southwest Western Australia
, which differs in its cones having several basal whorls of small sterile scales, and Neocallitropsis
from New Caledonia, distinct in its needle-like leaves throughout the life of the plant (not just seedlings) and always arranged in whorls of four (not three).
The wood of cypress-pines is light, soft and aromatic. It can be easily split and resists decay, cypress-pine also is termite resistant. It is used to make furniture, indoor and outdoor panelling, and fence posts. Cypress-pines are occasionally planted as ornamental trees, but their use is restricted by the high risks imposed by their very high flammability in bushfires.
Callitris columellaris is naturalised in southern Florida
, where it is usually known by the synonym Callitris glaucophylla.
In 2010, early Oligocene
fossilized foliage and cones of Callistris were unearthed near the Lea River in Tasmania
. The fossils were given the name Callitris leaensis and represent the oldest known representative of the genus.
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s in the Cupressaceae
Cupressaceae
The Cupressaceae or cypress family is a conifer family with worldwide distribution. The family includes 27 to 30 genera , which include the junipers and redwoods, with about 130-140 species in total. They are monoecious, subdioecious or dioecious trees and shrubs from 1-116 m tall...
(cypress family). There are 15 species in the genus, of which 13 are native to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and the other two (C. neocaledonica, C. sulcata) native to New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
. Traditionally the most widely used common name is cypress-pine, a name shared by the closely related genus Actinostrobus
Actinostrobus
Actinostrobus is a genus of coniferous trees in the Cupressaceae . Common names include cypress, sandplain-cypress and cypress-pine, the last of these shared by the closely related genus Callitris...
. However, this is inaccurate as these are just cypress and in no way pines, and they are increasingly being called cypress.
They are small to medium-sized tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s or large shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, reaching 5-25 m tall (to 40 m in C. macleayana). The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
and scale-like, except young seedlings, where they are needle-like; in C. macleayana, needle-like leaves are found mixed with scale leaves throughout the tree's life. The scales are arranged in six rows along the twigs, in alternating whorls of three (often in whorls of four in C. macleayana).
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
are small, 3-6 mm long, and are located at the tips of the twigs. The female cones start out similarly inconspicuous, maturing in 18-20 months to 1-3 cm long and wide, globular to ovoid (acute in C. macleayana), with six overlapping, thick, woody scales, arranged in two whorls of three (often 8 scales in C. macleayana). The cones remain closed on the trees for many years, opening only after being scorched by a bushfire; this then releases the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s to grow on the newly cleared burnt ground.
The genus is divided into two sections, with the atypical C. macleayana in sect. Octoclinis, and all the other species in sect. Callitris. Some botanists treat C. macleayana in a separate genus, as Octoclinis macleayana. C. macleayana is also distinct in occurring in rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
on the east coast of Australia; the other species all grow on dry sites.
The closest relatives of Callitris are Actinostrobus
Actinostrobus
Actinostrobus is a genus of coniferous trees in the Cupressaceae . Common names include cypress, sandplain-cypress and cypress-pine, the last of these shared by the closely related genus Callitris...
from southwest Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, which differs in its cones having several basal whorls of small sterile scales, and Neocallitropsis
Neocallitropsis
Neocallitropsis pancheri is a plant species of the family Cupressaceae and the sole species of the genus Neocallitropsis. It is endemic to New Caledonia, where it occurs in small, scattered population along rivers....
from New Caledonia, distinct in its needle-like leaves throughout the life of the plant (not just seedlings) and always arranged in whorls of four (not three).
The wood of cypress-pines is light, soft and aromatic. It can be easily split and resists decay, cypress-pine also is termite resistant. It is used to make furniture, indoor and outdoor panelling, and fence posts. Cypress-pines are occasionally planted as ornamental trees, but their use is restricted by the high risks imposed by their very high flammability in bushfires.
Callitris columellaris is naturalised in southern Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, where it is usually known by the synonym Callitris glaucophylla.
In 2010, early Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
fossilized foliage and cones of Callistris were unearthed near the Lea River in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
. The fossils were given the name Callitris leaensis and represent the oldest known representative of the genus.