''Taxus wallichiana'', the Himalayan yew, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
yew, native to the
Himalaya
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
and parts of south-east Asia. The species has a variety of uses in traditional medicine. It is currently classified as
endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...
by the
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
.
Distribution and habitat
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.
Growth
It is a medium-sized
evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
coniferous
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant ...
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
growing to 10 m tall, similar to ''
Taxus baccata
''Taxus baccata'' is a species of evergreen tree in the family Taxaceae, native to western, central and southern Europe (including Britain and Ireland), northwest Africa, northern Iran, and southwest Asia.Rushforth, K. (1999). ''Trees of Britain ...
'' and sometimes treated as a
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
of it. The shoots are green at first, becoming brown after three or four years. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are thin, flat, slightly
falcate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...
(
sickle
A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting succulent forage chiefly for feeding livestock, ei ...
-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
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...
, with the male and female
cones
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
A cone is formed by a set of line segments, half-lines, or lines conn ...
on separate plants; the seed cone is highly modified,
berry
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...
-like, with a single scale developing into a soft, juicy red
aril
An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ...
1 cm diameter, containing a single dark brown
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
7 mm long. The
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
cones are globose, 4 mm diameter, produced on the undersides of the shoots in early spring.
[
]
Species
Similar plants occurring further east through China to Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
, Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
and the Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
are included in ''Taxus wallichiana'' as ''T. wallichiana'' var. ''chinensis'' (Pilger) Florin by some authors,[ but are more often treated as a separate species '']Taxus chinensis
''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''.
This plant is used to produce medicines for cancer treatment, including Paclitaxel and T ...
''.[Rushforth, K. (1987). ''Conifers''. Helm .][Farjon, A. (1998). ''World Checklist and Bibliography of Conifers''. Royal Botanic Gardens, Kew .]
Medicinal uses
The tree has medicinal use in Ayurveda
Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population repo ...
and Tibetan medicine
Traditional Tibetan medicine (), also known as Sowa-Rigpa medicine, is a centuries-old traditional medical system that employs a complex approach to diagnosis, incorporating techniques such as pulse analysis and urinalysis, and utilizes behavior ...
. ''Taxus wallichiana'' is also a source of the chemical precursors to the anticancer An anticarcinogen (also known as a carcinopreventive agent) is a substance that counteracts the effects of a carcinogen or inhibits the development of cancer. Anticarcinogens are different from anticarcinoma agents (also known as anticancer or an ...
drug paclitaxel (taxol). ''Taxus wallichiana'' is used for making tea by the Bhotiya
Bhotiya or Bhot ( ne, भोटिया, ) are groups of ethno-linguistically related Tibetan people living in the Transhimalayan region that divides India from Tibet. The word ''Bhotiya'' comes from the classical Tibetan name for Tibet, , . ...
tribal community in the Garhwal Himalaya
The Garhwal Himalayas are mountain ranges located in the Indian state of Uttarakhand.
Geology
This range is also a part of Himalaya Sivalik Hills, the outer most hills of the Himalaya located in Himachal Pradesh and Uttarakhand.
Major peaks ...
. The stem bark of this species, which is locally known as ''thuner'', is collected for this purpose. This species is also used as fuelwood
Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form, compared to other forms of wood fuel like pellets or chips. Firewood can ...
by the local communities. In Himachal it is known to be medicine for some types of cancer.
Conservation
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
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...
by the IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
. 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.
References
{{Taxonbar, from=Q186553
wallichiana
Trees of Afghanistan
Flora of tropical Asia
Medicinal plants
Plants used in traditional Chinese medicine
Plants used in Ayurveda