Spores are liberated only after decay and decomposition of thallus in

Options

A. Marchantia
B. Anthoceros
C. Riccia
D. Funaria.

Answer

To solve the question "Spores are liberated only after decay and decomposition of thallus in," we need to analyze the options provided and understand the reproductive mechanisms of the organisms mentioned.

### Step-by-Step Solution:

1. **Understanding the Question**: The question is asking which organism releases its spores only after the decay and decomposition of its thallus.

2. **Analyzing the Options**: We have four options:
- Option 1: Mercantia
- Option 2: Anthoceros
- Option 3: Rixia
- Option 4: Funaria

3. **Evaluating Rixia**:
- Rixia is a genus of liverworts where the sporophyte is embedded within the gametophyte (thallus).
- The spores in Rixia are released only after the surrounding thallus tissue decays and decomposes. This process allows the spores to be liberated into the environment.

4. **Evaluating Funaria**:
- Funaria, a moss, has a fully developed sporophyte consisting of a foot, seta, and capsule.
- Spores are formed in the capsule and are released when the capsule matures and dries, not specifically after the decay of the thallus.

5. **Evaluating Mercantia**:
- Mercantia is another type of liverwort, but its sporophyte structure is different. It has a differentiated sporophyte that does not rely on the decay of the thallus for spore liberation.

6. **Evaluating Anthoceros**:
- Anthoceros has a mature sporophyte that is elongated and distinct. The spores are released from the sporophyte itself, not after the decay of the thallus.

7. **Conclusion**: Based on the analysis, the correct answer is **Rixia** (Option 3), as it is the only organism among the options that liberates spores after the decay and decomposition of the thallus.

### Final Answer:
**Rixia (Option 3)** is the correct answer.

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