Question: Taxus wallichiana (Himalayan Yew) — ecological significance, medicinal value, conservation status, and threats
Introduction
Taxus wallichiana, the Himalayan Yew, is a slow-growing conifer of immense ecological and pharmacological value, increasingly threatened by overextraction and habitat loss across the Himalayan and sub-Himalayan belt.
Body
1. State Symbol and Distribution
Taxus wallichiana is the State tree of Nagaland, underscoring its cultural and ecological salience in northeastern India. It is distributed across the Himalayas, Khasi Hills, and parts of Southeast Asia, typically occurring in moist temperate and subalpine forests between 1,800 and 3,300 metres.
2. Pharmacological Significance
The bark and needles of Himalayan Yew contain paclitaxel (taxol), a compound widely used in chemotherapy for breast, ovarian, and lung cancers. Commercial demand for taxol has driven unsustainable bark extraction, as the compound was historically obtained by felling mature trees rather than through cultivation or synthetic routes.
3. Conservation Status and Regulatory Framework
The species is listed under CITES Appendix II, which regulates international trade to prevent exploitation incompatible with species survival. It is also categorised as vulnerable on the IUCN Red List. Domestic protection is provided under the Indian Forest Act and State-level regulations, though enforcement in remote Himalayan terrain remains inconsistent.
4. Reproductive Biology and Regeneration Challenges
Taxus wallichiana is dioecious — male and female reproductive structures occur on separate individuals — which limits natural regeneration rates. Combined with its slow growth, this makes population recovery after disturbance particularly difficult, amplifying the conservation concern.
Conclusion
Balancing pharmaceutical demand with in-situ conservation requires scaling semi-synthetic paclitaxel production, strengthening CITES enforcement at trade nodes, and integrating Yew protection into Himalayan ecosystem management frameworks.
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PYQ 2026
Consider the following statements about Rhynchostylis retusa (Foxtail Orchid) :
1. It is an epiphytic orchid.
2. It is endemic to North-East India.
3. It is the State flower of Arunachal Pradesh and Assam.
Which of the above statements is/are correct ?
PYQ
Consider the following statements about Dipterocarpus macrocarpus (Hollong):
1. It is the State tree of Assam.
2. It belongs to the family Dipterocarpaceae.
3. It is the tallest tree species found in Indian forests.
4. It is commonly found in mangrove ecosystems of the Brahmaputra delta.
Which of the above statements is/are correct?
PYQ
Kokio (Kokai cookei), sometimes cited in Indian conservation discussions as a parallel case of ex-situ conservation success, is associated with which of the following?
1. It became functionally extinct in the wild before being saved by vegetative propagation.
2. It is a native tree species of Hawaii and belongs to the family Malvaceae.
3. Its conservation is managed by the Botanical Survey of India.
Which of the above statements is/are correct?
PYQ
Which of the following statements about the Dugong (Dugong dugon), which is the State animal of the Andaman and Nicobar Islands, is/are correct?
1. It is the only living representative of the family Dugongidae.
2. It feeds primarily on seagrasses and is therefore considered a keystone species in seagrass ecosystems.
3. It is listed as 'Critically Endangered' on the IUCN Red List.
4. It is protected under Schedule I of the Wildlife Protection Act, 1972.
Select the correct answer:
PYQ
Consider the following statements about Pterocarpus marsupium (Indian Kino Tree):
1. It is the State tree of Madhya Pradesh.
2. Its heartwood yields a substance called kino, used in traditional medicine for diabetes management.
3. It is listed as 'Vulnerable' on the IUCN Red List.
Which of the above statements is/are correct?