A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are a typically rather short-lived pioneer species widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates.
Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the temperate Northern Hemisphere, with a few species reaching the Southern Hemisphere in the Andes in South America. Their typical flowers are catkins and often appear before leaves.
Hornbeams are hardwood trees in the flowering plant genus Carpinus in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.
The hazel (Corylus) is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae. The fruit of the hazel is the hazelnut.
Ironwood is a common name for many woods or plants that have a reputation for hardness, or specifically a wood density that is heavier than water, although usage of the name ironwood in English may or may not indicate a tree that yields such heavy wood.
Tsuga is a genus of conifers in the subfamily Abietoideae of Pinaceae, the pine family. The common name hemlock is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock. Unlike the latter, Tsuga species are not poisonous.
Parrotia persica, the Persian ironwood, is a deciduous tree in the family Hamamelidaceae, closely related to the witch-hazel genus Hamamelis. It is native to Iran's Caspian region and Iranian Azerbaijan. It is endemic in the Alborz mountains, where it is found mainly in Golestan National Park.
Ostryopsis is a small genus of deciduous shrubs belonging to the birch family Betulaceae. The species have no common English name, though hazel-hornbeam has been suggested, reflecting their similarities to the closely related hazels and hop-hornbeams.
Teucrium is a cosmopolitan genus of flowering plants in the family Lamiaceae, commonly known as germanders. Plants in this genus are perennial herbs or shrubs, with branches that are more or less square in cross-section, leaves arranged in opposite pairs, and flowers arranged in thyrses, the corolla with mostly white to cream-coloured, lobed petals.
Sparganium (bur-reed) is a genus of flowering plants, described as a genus by Linnaeus in 1753. It is widespread in wet areas in temperate regions of both the Northern and Southern Hemispheres. The plants are perennial marsh plants that can grow to 3.5 m, with epicene flowers.
TrachelospermumStar Jasmine, Confederate Jasmine, is a genus of evergreen woody vines in the dogbane family Apocynaceae, first described as a genus in 1851. All species are native to southern and eastern Asia.
Aucuba is a genus of three to ten species of flowering plants, now placed in the family Garryaceae, although formerly classified in the Aucubaceae or Cornaceae.
Ostrya virginiana, the American hophornbeam, is a species of Ostrya native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Populations from Mexico and Central America are also regarded as the same species, although some authors prefer to separate them as a distinct species, Ostrya guatemalensis. Other names include eastern hophornbeam, hardhack, ironwood, and leverwood.
Ostrya rehderiana is a tree in the Betulaceae family. It can grow up to 15 metres (49 ft) tall. It is endemic to Zhejiang province in China. The wild population apparently consists of only five trees on Tianmu Mountain, and the species is under first-class national protection in China.
Ostrya carpinifolia, the European hop-hornbeam, is a tree in the family Betulaceae. It is the only species of the genus Ostrya that is native to Europe.
Ostrya knowltonii is a species of tree known by the common names Knowlton's hophornbeam, western hophornbeam, woolly hophornbeam, and wolf hophornbeam. It is also one of many trees called ironwood. It is native to Utah, Arizona, New Mexico, and Texas in the United States, but its distribution is localized and sporadic.
Eucommia is a genus of small trees now native to China, with a fossil record that shows a much wider distribution. The single living species, Eucommia ulmoides, is near threatened in the wild, but is widely cultivated in China for its bark, and is highly valued in herbology such as traditional Chinese medicine.
Ostrya chisosensis, common name Big Bend hop-hornbeam or Chisos hop-hornbeam, is a plant species endemic to Texas. It is known only from the Chisos Mountains inside Big Bend National Park, in Brewster County, although related populations in northern Chihuahua have not been studied in detail and may be the same species. It grows along streambanks and on the walls of canyons.
