Tap root system - Dicots
Fibrous root system - Monocots
Fasciculated roots - Curcuma
Stilt roots - Sugarcane

In plants, roots are responsible for anchoring the plant, absorbing water and nutrients from the soil, and storing food. There are two main types of root systems: tap root system and fibrous root system.

Tap root system:
- A tap root system consists of a single main root, known as the tap root, that grows vertically downward.
- The tap root is thick and long, and it gives rise to lateral branches called secondary roots.
- Dicot plants usually have a tap root system, as it allows for deeper penetration into the soil, providing better stability and access to water and nutrients.
- Examples of dicots with tap root systems include trees like oak, mango, and neem.

Fibrous root system:
- A fibrous root system consists of numerous thin, branching roots that arise from the base of the stem.
- These roots spread out horizontally in all directions, occupying the upper layers of the soil.
- Monocot plants generally have fibrous root systems, which provide better anchorage and surface area for water and nutrient absorption.
- Examples of monocots with fibrous root systems include grasses like wheat, rice, and maize.

Fasciculated roots - Curcuma:
- Fasciculated roots are a type of modified adventitious roots that arise from the base of the stem in clusters or bundles.
- These roots are thick, fleshy, and cylindrical in shape, and they store food and water.
- Curcuma, commonly known as turmeric, is a monocot plant that has fasciculated roots.
- The roots of Curcuma are used for the extraction of turmeric, which is a widely used spice and medicinal herb.

Stilt roots - Sugarcane:
- Stilt roots are adventitious roots that emerge from the lower nodes of the stem and grow vertically downward into the soil.
- These roots provide additional support to the plant and help in anchoring it firmly in the ground.
- Sugarcane, a type of monocot plant, possesses stilt roots that aid in supporting its tall and heavy stem.

Therefore, the mismatched pair in the given options is "Fasciculated roots - Curcuma" as Curcuma is a monocot plant and monocots generally have fibrous root systems, not fasciculated roots.