The lightest wood is

Options

A. Cereus gigantus
B. Ochroma lagopus
C. Hardwickia binata
D. Cycas

Answer

To determine which wood is the lightest among the given options, we will analyze each option based on their characteristics and properties.

### Step-by-Step Solution:

1. **Identify the Options**: The question provides several options for the lightest wood. We will evaluate each one to determine which is the lightest.

2. **Evaluate Sirus giganteus**:
- This option refers to a large cactus.
- Cacti do not produce wood in the traditional sense as they are primarily composed of succulent tissues.
- **Conclusion**: This option is incorrect.

3. **Evaluate Okruma legopus** (Balsa wood):
- Okruma legopus, commonly known as balsa, is a species of flowering plant from the Malvaceae family.
- Balsa wood is known for its very low density, making it one of the lightest woods available.
- It is classified as sapwood, which is functional and has a low density.
- **Conclusion**: This option is correct as it is recognized as the lightest wood.

4. **Evaluate Hardwicchia binata**:
- This is a flowering plant belonging to the Fabaceae family (legumes).
- While it may produce wood, it is not known for being particularly light.
- **Conclusion**: This option is incorrect.

5. **Evaluate Cyclus**:
- Cyclus refers to a type of pine that does not produce particularly light or durable wood.
- It has a palm-like appearance but is not a true palm.
- **Conclusion**: This option is also incorrect.

6. **Final Conclusion**: After evaluating all the options, the lightest wood is **Okruma legopus** (Balsa wood).