CDS (II) 2023 General Knowledge · Question 81 of 120

Correct — A, Cashewnut and Magnolia. The pair fails because of the cashew. Cashew is a tropical tree, grown between about 25 degrees north and 25 degrees south and suited to hot lowland country with a marked dry season — in India that means the coastal belts of Kerala, Karnataka, Goa, Maharashtra, Tamil Nadu, Andhra Pradesh and Odisha, at or near sea level. It has no place in the temperate belt of the Himalaya, roughly 1,500 to 3,000 metres, where winter frost is normal. Magnolia, by contrast, does belong there: Magnolia campbellii grows in sheltered Himalayan valleys from eastern Nepal through Sikkim and Assam into southern Tibet, Yunnan and northern Myanmar. So one member of the set belongs and one cannot, and a set is only as good as its weakest member. The other three options are drawn straight from the temperate Himalayan flora — oak and maple, rhododendron, birch and laurel.

• (b)Oak and Maple — Both are standard broad-leaved trees of the Himalayan temperate belt; oak forests are the dominant cover over large parts of the western and central Himalaya at these heights.
• (c)Rhododendrons — Rhododendron is the signature genus of the temperate and sub-alpine Himalaya, especially in Sikkim and Arunachal Pradesh. It is also the one option that names a single genus where the others name pairs, which can make it look out of place — that oddity is in the printing, not in the botany.
• (d)Birch and Laurels — Birch is the tree of the upper temperate and treeline zone of the Himalaya, and laurels are common in the moist temperate and sub-tropical evergreen belt below it.

Himalayan vegetation changes with altitude rather than with latitude. Up to about 1,000 metres the cover is tropical moist deciduous and sub-tropical evergreen; between roughly 1,500 and 3,000 metres lies the temperate montane belt of oak, chestnut, maple, laurel, magnolia, rhododendron and the conifers — deodar, chir pine, silver fir and spruce; above that comes birch and stunted rhododendron at the treeline, then alpine meadow. The tropical plantation and orchard crops of the peninsula — cashew, coconut, rubber, arecanut — belong to an entirely different climatic band.

This is a set question, so the discipline is to test every member and reject the whole set on one failure. Three of the four options are pure temperate-Himalayan lists, which makes the odd one easy to spot once you notice that cashew is a coastal crop of the hot lowlands. A useful cross-check is frost: cashew flowers and fruits are damaged by it, which is why plantations sit near the coast and rarely far above sea level, while the temperate Himalayan belt has frost as a normal part of winter. Magnolia is the member most students hesitate over, and it is worth remembering as a Himalayan tree in its own right — Magnolia campbellii is one of the flowering trees of the eastern Himalayan spring.

• The cashew tree is cultivated in the tropics between about 25 degrees north and 25 degrees south, suited to hot lowland areas with a pronounced dry season.
• Magnolia campbellii grows in sheltered Himalayan valleys from eastern Nepal and Sikkim through Assam into southern Tibet, Yunnan and northern Myanmar.
• The Himalayan temperate montane belt runs roughly from 1,500 to 3,000 metres and carries oak, chestnut, maple, laurel, magnolia and rhododendron along with conifers.
• Birch marks the upper temperate and treeline zone, above which only alpine meadow survives.
• India's cashew growing is concentrated in the coastal States — Kerala, Karnataka, Goa, Maharashtra, Tamil Nadu, Andhra Pradesh and Odisha.

• Rejecting magnolia as exotic; it is a genuine Himalayan temperate tree.
• Judging the set by its first-named member only — the question is about the pair, and one failure sinks it.
• Assuming rhododendron is alpine only; it spans the temperate and sub-alpine belts.

As a set-of-trees item where one tropical species is slipped into a temperate list, or as an altitude-to-vegetation matching question.

• practice — not a real PYQ

  Which one of the following trees is characteristic of the treeline zone of the Himalaya?

  • (a)Cashew
  • (b)Birch
  • (c)Rubber
  • (d)Teak

  Answer(b) Birch — it forms the uppermost forest belt of the Himalaya, just below the alpine meadows.

• practice — not a real PYQ

  Cashew cultivation in India is concentrated in which one of the following?

  • (a)The temperate Himalayan valleys
  • (b)The coastal plains of the peninsula
  • (c)The Thar desert margins
  • (d)The Chotanagpur plateau above 1,500 metres

  Answer(b) The coastal plains of the peninsula — cashew is a tropical lowland crop needing a hot climate with a pronounced dry season.