| Taxus wallichiana | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Taxaceae |
| Genus: | Taxus |
| Species: | T. wallichiana |
| Binomial name | |
| Taxus wallichiana | |
| Synonyms [3] [4] | |
List
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Taxus wallichiana, the Himalayan yew, is a species of yew, native to the Himalaya and parts of south-east Asia. The species has a variety of uses in traditional medicine. It is currently classified as endangered by the IUCN.
The species favours a reasonably wide range of habitats, growing in montane, temperate, warm temperate, and tropical submontane to high montane forests which may be deciduous, evergreen, or of mixed character. In forests, it tends to present as a low canopy tree; in open situations it usually forms a large, broadly spreading shrub. Elevation ranges from 900 m to 3,700 m. [1]
It is a medium-sized evergreen coniferous tree growing to 10 m tall, similar to Taxus baccata and sometimes treated as a subspecies of it. The shoots are green at first, becoming brown after three or four years. The leaves are thin, flat, slightly falcate (sickle-shaped), 1.5–2.7 cm long and 2 mm broad, with a softly mucronate apex; they are arranged spirally on the shoots but twisted at the base to appear in two horizontal ranks on all except for erect lead shoots. It is dioecious, with the male and female cones on separate plants; the seed cone is highly modified, berry-like, with a single scale developing into a soft, juicy red aril 1 cm diameter, containing a single dark brown seed 7 mm long. The pollen cones are globose, 4 mm diameter, produced on the undersides of the shoots in early spring. [5]
Similar plants occurring further east through China to Taiwan, Vietnam and the Philippines are included in Taxus wallichiana as T. wallichiana var. chinensis (Pilger) Florin by some authors, [3] but are more often treated as a separate species Taxus chinensis . [5] [6]
The tree has medicinal use in Ayurveda and Tibetan medicine. Taxus wallichiana is also a source of the chemical precursors to the anticancer drug paclitaxel (taxol). [7] Taxus wallichiana is used for making tea by the Bhotiya tribal community in the Garhwal Himalaya. The stem bark of this species, which is locally known as thuner, is collected for this purpose. This species is also used as fuelwood by the local communities. In Himachal it is known to be medicine for some types of cancer. [8]
The Himalayan yew has been subject to heavy exploitation for its leaves and bark across most of its range through the Himalayas and western China. Declines have been particularly heavy in India and Nepal, with losses of up to 90% having been reported. The degree of exploitation in other locations in its range is less well known, but is also assumed to be serious. The species is currently classified as endangered by the IUCN. It is present in several protected areas, and at least some conservation and propagation measures are underway, with an eye to its commercial value in the medicine trade. [1]
Taxus is a genus of coniferous trees or shrubs known as yews in the family Taxaceae. Yews occur around the globe in temperate zones of the northern hemisphere, northernmost in Norway and southernmost in the South Celebes. Some populations exist in tropical highlands.
Taxaceae, commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species.
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.
Pinus wallichiana is a coniferous evergreen tree native to the Himalaya, Karakoram and Hindu Kush mountains, from eastern Afghanistan east across northern Pakistan and north west India to Yunnan in southwest China. It grows in mountain valleys at altitudes of 1800–4300 m, reaching 30–50 m (98–164 ft) in height. It favours a temperate climate with dry winters and wet summers. In Pashto, it is known as Nishtar.
Tsuga heterophylla, the western hemlock or western hemlock-spruce, is a species of hemlock native to the west coast of North America, with its northwestern limit on the Kenai Peninsula, Alaska, and its southeastern limit in northern Sonoma County, California. The Latin species name means 'variable leaves'.
Taxus brevifolia, the Pacific yew or western yew, is a species of tree in the yew family Taxaceae native to the Pacific Northwest of North America. It is a small evergreen conifer, thriving in moisture and otherwise tending to take the form of a shrub.
Papuacedrus papuana is a species in the conifer family Cupressaceae, the sole species in the genus Papuacedrus. Some botanists do not consider this species as forming a distinct genus, but include it in the related genus Libocedrus. It is native to New Guinea and to the Indonesian Province of Maluku.
Juniperus procumbens is a species of shrub in the cypress family Cupressaceae, native to Japan. This low-growing evergreen conifer is closely related to the Chinese juniper, Juniperus chinensis, and is sometimes treated as a variety of it, as J. chinensis var. procumbens.
Juniperus squamata, the flaky juniper, or Himalayan juniper is a species of coniferous shrub in the cypress family Cupressaceae, native to the Himalayas and China.
Cupressus cashmeriana, the Bhutan cypress or Kashmir cypress, is a species of evergreen conifer native to the eastern Himalaya in Bhutan and adjacent areas of Arunachal Pradesh in northeastern India. [ Now in vulnerable category, IUCN list retrieved in 2006 ]. It is also introduced in China and Nepal. It grows at moderately high altitudes of 1,250–2,800 metres (4,100–9,190 ft).
Calocedrus formosana is a conifer endemic to Taiwan.
Taxus chinensis is a species of yew. It is commonly called the Chinese yew, though this term also refers to Taxus celebica or Taxus sumatrana.
Taxus floridana, the Florida yew, is a species of yew, endemic to a small area of under 10 km² on the eastern side of the Apalachicola River in mesophytic forests of northern Florida at altitudes of 15–40 m. It is listed as critically endangered. It is protected in reserves at the Torreya State Park and at the Nature Conservancy's Apalachicola Bluffs and Ravines Preserve, and has legal protection under the United States and Florida Endangered Species laws.
Taxus sumatrana, or the Sumatran yew, is a large evergreen shrub and one of the eight species of yew. Its taxonomic namesake is indicative of the species being found in Indonesia ; however, T. sumatrana is also found in a number of South and Southeast Asian countries, including parts of Afghanistan, Bangladesh, Bhutan, China, India, Indochina, Nepal, Pakistan, the Philippines, Taiwan, and Tibet. Given this broad geographical range, it is also known as the Taiwan yew, the Chinese yew, as well as the East Himalayan yew. Plants of the World Online recognizes T. sumatrana as a synonym of Taxus wallichiana.
Tsuga chinensis, commonly referred to as the Taiwan or Chinese hemlock, or in Chinese as tieshan, is a coniferous tree species native to China, Taiwan, Tibet and Vietnam. The tree is quite variable and has many recognised varieties, though some are also maintained to be separate species by certain authorities. The tree was recently discovered in the mountains of northern Vietnam, making that the southernmost extension of its range.
Abies chensiensis, the Shensi fir, is a fir native to Gansu, Hubei, Sichuan, Tibet, Yunnan in China, and Arunachal Pradesh in India. It was first described by Philippe Édouard Léon Van Tieghem in 1892.
Athrotaxis laxifolia is a species of tree belonging to the genus Athrotaxis endemic to Tasmania.
Juniperus semiglobosa, the Himalayan pencil juniper, is a species of juniper native to the mountains of Central Asia, in northeastern Afghanistan, westernmost China (Xinjiang), northern Pakistan, southeastern Kazakhstan, Kyrgyzstan, western Nepal, northern India, Tajikistan, and Uzbekistan. It grows at altitudes of 1,550–4,420 metres.
Libocedrus plumosa, with the common name kawaka, is a species of Libocedrus that is endemic to New Zealand.
Nageia wallichiana is a species of conifer in the family Podocarpaceae. It is a tree 10–54 m high, found in Brunei, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. Nageia wallichiana is the most widely distributed species among the seven species in the genus Nageia. If the land areas of China and Japan are excluded, its distribution nearly coincides with that of the genus and includes both the western outliers in India and the easternmost part on Normanby Island. It is one of the most extensive conifer ranges recognized and is similar to Dacrycarpus imbricatus and Podocarpus neriifolius.
