Aug 2023
The hardy genus Takakia has survived 400 million years but is losing ground in the Himalayas
The fastest-evolving moss in the world may not adapt to climate change
Jan 2016
Many trees enjoy extremely long lives in comparison to humans and other animals. Yet one group of trees, the bristlecone pines, stands out as the most ancient of all, with individual trees that commonly live for thousands of years, including one that has survived more than 5000 years. See also: Tree
Bristlecone pines are the oldest living trees
Jan 2015
Conifers are predominantly cone-bearing, evergreen trees and shrubs belonging to the order Pinales, as well as a small number of extinct orders, in the class Pinopsida of the division Pinophyta (Coniferophyta). All are woody plants, and they are often the predominant trees of forests worldwide, including pine, spruce, fir, hemlock, cedar, larch, juniper, cypress, yew, and redwood species. Because the ovules (young seeds) of these plants are exposed directly to the air at the time of pollination—that is, these plants produce seeds that are not enclosed in a fruit or ovary—conifers are classified as gymnosperms. (In contrast, the flowering plants, or angiosperms, have ovules enclosed in an ovary.) Today, conifers constitute the principal source of lumber and pulp for paper and wood products. See also: Forest and forestry; Forest timber resources; Lumber; Pinales; Pinophyta; Pinopsida; Tree; Wood products
Conifers
Jan 2015
The olive tree (Olea europaea) is an ancient cultivated plant that was originally domesticated by early civilizations in the eastern Mediterranean regions. Today, the major olive-producing countries are Spain, Italy, Greece, and Turkey, which provide about 60–70% of the world's olives. However, the olive trees of Italy are being threatened by the spread of a deadly bacterial pathogen, Xylella fastidiosa, which causes olive leaf scorch. Specifically, the bacterium prevents water movement (via the xylem transport system) in infected trees, causing the leaves of the olive tree to turn yellow and brown, and then fall off. The loss of leaves is in turn followed by a withering of the branches, and the tree eventually collapses and dies. So far, the bacterium is decimating the olive groves located in the Apulia region of southern Italy. The pathologic condition, termed olive quick decline syndrome (OQDS), is a serious one, and it is feared that it will spread to other olive-growing areas of Europe. It is also possible that the bacterium may infect other fruiting trees and plants, including plum, almond, and citrus fruit trees, as well as grapevines. See also: Domestication (anthropology); Fruit; Fruit, tree; Horticultural crops; Lamiales; Olive; Plant pathology; Plant-water relations; Xylem
Olive trees in danger