Question

Identify the special tissue in the epiphytic roots of orchids that absorbs atmospheric moisture.

• A. Cortex
• B. Velamen
• C. Endodermis
• D. Pericycle

Hint:

Velamen is a characteristic adaptation of epiphytic orchids. It is a multilayered epidermis made of dead cells that absorbs atmospheric moisture rapidly and protects aerial roots.

Answer 1

The Correct Option is B

Concept: Epiphytic plants grow on other plants mainly for physical support and not for nutrition. Orchids are a common example of epiphytes. Since these plants often grow on tree branches and not directly in soil, they must obtain water and nutrients from the surrounding air, rainwater, and organic debris. To adapt to this lifestyle, orchid roots develop a specialized multilayered tissue called velamen. Velamen is composed of several layers of dead cells with thickened cell walls. These cells have large empty spaces that allow them to absorb and store atmospheric moisture quickly. Key functions of velamen include:
• Rapid absorption of atmospheric moisture such as rainwater, dew, or humidity.
• Protection of the inner living root tissues from excessive water loss.
• Mechanical protection of roots from damage and sunlight exposure.
• Temporary storage of water and dissolved minerals. This adaptation allows orchids to survive in habitats where direct soil water is unavailable.

Step 1: Understanding the habitat of epiphytic orchids.
Epiphytic orchids grow attached to tree trunks or branches. Because they do not grow in soil, they cannot absorb water through soil like most terrestrial plants.

Step 2: Identifying the specialized root structure.
The aerial roots of orchids are covered with a thick, spongy tissue known as velamen. This tissue efficiently absorbs moisture from the surrounding atmosphere.

Step 3: Selecting the correct option.
Among the given options:
• Cortex – general storage tissue in roots
• Velamen – specialized tissue in orchid roots
• Endodermis – regulates water entry into vascular tissues
• Pericycle – involved in lateral root formation Therefore, the correct answer is Velamen.