Pinales description

Pinales Dumort. 1829

Common names
Conifers.

Taxonomic notes
In the Database, all conifers are assigned to the Order Pinales. As treated here, the Pinales include 6 families and 601 species.

Some authors segregate the yews and plum-yews (Taxaceae and Cephalotaxaceae) as Order Taxales, and there is general agreement that they warrant distinction above the rank of family. Some authors segregate the family Cupressaceae into two families, Cupressaceae and Taxodiaceae; see Cupressaceae for relevant remarks. Reveal (2) proposes that the conifers be assigned to Class Pinopsida Burnett 1835, with most of the families thereunder elevated to the rank of Order. However, he further retains all families as treated here, with one exception: the genus Phyllocladus, here assigned to the Podocarpaceae, is raised to the rank of Family within Order Podocarpales Pulle ex Reveal 1992.

Description
Conifers usually have needle-shaped or scalelike leaves, and nearly all are evergreen. They typically have straight trunks with horizontal branches varying more or less regularly in length from bottom to top, so that the trees are conical in outline (1). Characterized by having staminate or pollen-producing cones; most bear ovulate or seed-producing cones (2).

Range
Cosmopolitan, excepting polar regions, the highest mountains, the driest deserts, and a few oceanic islands.

Big Tree
See Sequoiadendron giganteum.

Oldest
See Pinus longaeva

Dendrochronology

Ethnobotany
Conifers are one of the world's most important renewable resources (1).

Remarks
The Coniferales is by far the largest of the five gymnosperm orders, comprising about 610 of the 747 described species. Except for 20 species in the order Taxales (which some taxonomists call the family Taxaceae in the Coniferales), they include all of the conifers.

Conifer is the common name for a group of plants characterized by seed-bearing cones. Conifers are known from fossils more than 290 million years old. Although more species of conifers once existed, they are still a widely distributed group.

Conifers reproduce by means of seeds borne on the scales of female cones, and the pollen is produced in separate male cones. Pollination in conifers is always dependent on wind currents to blow the abundant yellow pollen from the male cones to the female cones (1).

Citations
(1) Encarta 97: "Gymnosperms" and "Conifers,".
(2) van Gelderen et al. 1986.
(3) Silba 1986.