Plants are often thought of as stationary organisms, “rooted” in one place. But did you know that in the struggle for survival, they are actually master travelers? The IELTS reading passage “Travelling Plants” unveils a mysterious world where plants move, explode, and even “hitchhike” on animals to ensure their survival.

This ECE article provides a translation, vocabulary analysis, and detailed answer explanations, helping you conquer one of the most fascinating Biology topics in IELTS Reading.

Reading Passage

Travelling Plants

Plants need to produce more individuals of their own kind, and these normally grow best from their parents. So plants need to travel, and they do so in a variety of ways.

In an English woodland, the blackberry puts out exploratory stems, which curve upwards, waving slowly as though searching. If they touch another plant, they begin to advance directly and purposefully. To us, their motion is invisible, but for a plant it’s an extraordinary rate – around five centimetres a day. When a stem makes contact with the ground, it puts down small rootlets, and starts to extract nutriment.

The silverweed is equally effective, putting out travelling stems that advance horizontally, creeping at low level through the mat of rootlets and dead vegetation formed by other plants.

In meadows, fescue grass is notable for annexing land from other less robust and aggressive species. The genetic fingerprints of its leaves and stems taken two hundred metres apart have proved, in some instances, to be identical. This must mean that one particularly vigorous plant has increased its territory year after year until now, after perhaps a century, it has become the largest plant in the entire meadow.

The bird-cage plant grows among sand dunes, in the deserts of the American west, and puts down long roots to search for water. But if the sand blows away, the plant’s roots may shrivel up, the plant dies, and the stems form a hollow sphere. With no roots to anchor it, the wind blows it across the sand for several kilometres. Eventually it rolls into a sheltered site, allowing the seeds inside to germinate.

A few plants don’t need external assistance to distribute their seeds. The Mediterranean squirting cucumber fills with a slimy juice as it ripens. Eventually the juice shifts so violently that the cucumber bursts off its stalk and shoots five or six metres through the air, leaving a trail of slime and seeds behind it.

One of the most dramatic detonating seed-containers belongs to a Brazilian tree known as monkey’s dinner-bell. The side of the seed pod facing the sun dries out, causing an explosion which can hurl the seeds over twelve metres. The bang is enough to convince nervous strangers in the forest that they’re under attack.

It’s particularly important for trees that their seeds move far enough away to gain adequate light and nutriment. This is helped by the height of the tree, and in some cases by fitting their seeds with wings. Sycamore seeds, for instance, have a single wing, sprouting from one side. This makes the seed spin, and even in a light breeze, these tiny spinning helicopters can land far from their parent.

Instead of using wind or water as carriers, many plants use animals. The South African grapple plant, a low-growing creeper, relies on its seeds being trodden on. Its seed capsules have arms ending in hooks that are so sharp and strong, and point in so many directions, that when the foot of an elephant or rhino descends on one, the capsule becomes attached, and is carried by the animal. Other plants reward their carriers instead of hurting them. Many plants that grow in the heathland of South Africa provide their seeds with an edible covering which ants find particularly attractive. These collect the seeds and carry them down to their underground nests, where they eat the covering, leaving the seeds themselves in an ideal position to germinate. Fruit seeds are completely enclosed with such a generous edible reward that the animal-carrier is encouraged to swallow both together. While the plant is constructing the seeds, the flesh of the unripe fruit is sour, and animals learn not to eat it.

But once the seeds are fully developed, the sap becomes sweet, and the fruit signals the fact that the seeds are now ready for transport by changing colour. Animals understand the signals well. They now eat the fruit, and carry the seed away inside their stomachs, to be ejected at a distance. Not all seeds have to pass through the entire digestive tract to be transported, though. The quetzal, a Central American bird, feeds on the wild avocado, swallowing it whole. It eventually regurgitates the stone, which then has a chance to take root and produce a new plant. Passage through an animal’s gut is essential for some seeds, however. When the acacia of East Africa produces its seed-bearing pods, beetles fly in, lay eggs, and as the grubs hatch, they feed on the acacia seeds. The seeds can only grow if an elephant, or other animal, eats the pod, as its digestive juices kill the eggs. Eventually the seeds return to the outside world in the animal’s droppings, and can germinate.

While the seeds of pine trees are developing, they’re protected inside cones. When the seeds are ripe, one bird, the nut-cracker, is particularly skilful at picking them out. Those it can’t eat immediately it buries, providing the seed with ideal growing conditions. But two out of every three seeds that the bird buries, it never finds again, so the tree uses a strategy of sacrificing a few of its seeds and relying on the poor memory of the courier who takes and conceals them.

So in one way or another, many seeds reach destinations where they can start their lives away from the environmental dominance of their parents.

Question 27 – 33: Complete each sentence with the correct ending, A–I, below.

27. The blackberry

28. The silverweed

29. Fescue grass

30. The bird-cage plant

31. The Mediterranean squirting cucumber

32. Monkey’s dinner-bell

33. The sycamore

Possible endings

A. can dominate its surroundings with a single plant.
B. explodes as a result of internal pressure.
C. has seeds which have a feature that increases the distance they travel.
D. colonises a new spot when it can no longer survive in another.
E. moves along close to the ground.
F. produces a loud noise when it distributes its seeds.
G. relies on human activity to distribute its seeds.
H. requires water every day.
I. produces branches that spread out very quickly into the air.

Question 34 – 39: Choose ONE WORD ONLY from the passage for each answer.

34. South African heathland plants are covered with a substance that appeals to …….

35. The seeds of South African heathland plants are carried into ….. in the earth.

36. Animals don’t like to eat …….. that is unripe because of the taste.

37. The quetzal ejects the ……… of the wild avocado through its mouth.

38. Pine seeds are contained in their ……… until they are mature.

39. The pine tree benefits because the nut-cracker bird has a bad …………

Question 40: Choose the correct letter, A, B, C, or D.

A. The movement of plants provides benefits for animals and other creatures.

B. Plants can move much faster than is generally realised.

C. The methods by which plants move are adapted to their surroundings.

D. Animals play a significant role in the movement of plants.

Summary of the reading passage

The “Travelling Plants” passage describes the diverse strategies plants use to move and disperse seeds to ensure the survival of their species.

Physical movement: Some plants actively extend their stems, such as the Blackberry (reaching upwards) or Silverweed (creeping along the ground).
Genetic dominance: Fescue grass expands its territory through vigorous growth, with a single plant capable of taking over an entire meadow.
Utilizing wind & mechanics: The bird-cage plant rolls with the wind after dying. The Squirting cucumber and Monkey’s dinner-bell use internal pressure or drying to “explode” and launch seeds. The Sycamore tree equips its seeds with “wings” to travel via the wind.
Utilizing animals:
- Attachment: The Grapple plant has sharp hooks to latch onto the feet of large animals.
- Food rewards: South African plants coat seeds in an edible substance to entice ants to carry them to their nests. Fruit-bearing plants change color when ripe to signal animals to eat them and disperse seeds through their digestive tracts.
- Complex symbiosis: The Acacia tree relies on elephants to eat its pods, as digestive juices kill beetle larvae that would otherwise destroy the seeds. Pine trees benefit from the poor memory of the Nut-cracker bird, which buries seeds and forgets where they are, allowing them to germinate.

Key Vocabulary

extract nutriment (v.p): to absorb nutrients.
vegetation (n): plant life in a particular area.
annexing (v): to take over or add territory.
- Example: “…notable for annexing land from other… species.”
vigorous (adj): strong, healthy, and full of energy.
shrivel up (v): to shrink and wrinkle, often due to dryness.
germinate (v): to begin to grow (of a seed).
detonating (adj): having the quality of exploding.
- Example: “…dramatic detonating seed-containers…”
hurl (v): to throw with great force.
descends on (v): to land or step upon.
regurgitates (v): to bring swallowed food back up to the mouth.
- Example: “It eventually regurgitates the stone…”
dominance (n): the state of being more powerful or prevalent.

Answers and Detailed Explanations

Questions 27 – 33 (Matching Endings)

27. I (The blackberry… produces branches that spread out very quickly into the air)

Evidence: “puts out exploratory stems, which curve upwards… extraordinary rate – around five centimetres a day.”
Explanation: “Curve upwards” corresponds to “spread out into the air.” “Extraordinary rate” corresponds to “very quickly.”

28. E (The silverweed… moves along close to the ground)

Evidence: “…putting out travelling stems that advance horizontally, creeping at low level…”
Explanation: “Creeping at low level” is synonymous with “moves along close to the ground.”

29. A (Fescue grass… can dominate its surroundings with a single plant)

Evidence: “…one particularly vigorous plant has increased its territory… became the largest plant in the entire meadow.”
Explanation: A single plant expanding its territory to become the largest in the meadow means it “dominates its surroundings.”

30. D (The bird-cage plant… colonises a new spot when it can no longer survive in another)

Evidence: “…if the sand blows away, the plant dies… wind blows it… Eventually it rolls into a sheltered site, allowing the seeds inside to germinate.”
Explanation: When it can no longer survive (dies), it rolls to a new location (sheltered site) to germinate (colonise a new spot).

31. B (The Mediterranean squirting cucumber… explodes as a result of internal pressure)

Evidence: “…fills with a slimy juice… juice shifts so violently that the cucumber bursts off…”
Explanation: The pressure of the liquid (juice shifts violently) causes the fruit to “burst” (explode). This is internal pressure.

32. F (Monkey’s dinner-bell… produces a loud noise when it distributes its seeds)

Evidence: “…causing an explosion… The bang is enough to convince nervous strangers… that they’re under attack.”
Explanation: “The bang” is the “loud noise.”

33. C (The sycamore… has seeds which have a feature that increases the distance they travel)

Evidence: “…fitting their seeds with wings… make the seed spin… can land far from their parent.”
Explanation: The feature is the “wings,” which help the seeds travel further.

Questions 34 – 39 (Sentence Completion)

34. ants

Evidence: “…edible covering which ants find particularly attractive.”
Explanation: The covering attracts “ants.”

35. nests

Evidence: “These collect the seeds and carry them down to their underground nests…”
Explanation: The seeds are carried into the “nests.”

36. fruit

Evidence: “While the plant is constructing the seeds, the flesh of the unripe fruit is sour, and animals learn not to eat it.”
Explanation: Animals avoid eating “fruit” when it is unripe.

37. stone

Evidence: “It eventually regurgitates the stone, which then has a chance to take root…”
Explanation: The quetzal regurgitates the “stone” (the avocado pit).

38. cones

Evidence: “While the seeds of pine trees are developing, they’re protected inside cones.”
Explanation: Pine seeds are protected inside “cones.”

39. memory

Evidence: “…relying on the poor memory of the courier who takes and conceals them.”
Explanation: The tree benefits from the bird’s poor “memory.”

Question 40 (Multiple Choice)

40. C (The methods by which plants move are adapted to their surroundings)

Explanation:
- A (Benefits for animals): Only true for a small part of the passage.
- B (Plants move faster than realised): Only true for the Blackberry.
- D (Animals play a significant role): Only true for the latter part of the passage.
- C (Methods are adapted to surroundings): This is the most comprehensive answer. The passage lists various methods (wind, explosion, creeping, animal transport) that are each uniquely suited to the plant’s specific environment (desert, forest, meadow, etc.).

Conclusion

“Travelling Plants” is an exemplary reading passage about the natural world, showcasing the infinite creativity of plants in their quest for survival. It not only provides rich botanical vocabulary but also serves as an excellent exercise for honing skills in matching information and finding specific details. Understanding the adaptation mechanisms of each plant is the key to answering these questions accurately.