Question

Censer mechanism for spore dispersal from the capsule occurs in __________________.

• A. Pellia
• B. Funaria
• C. Pogonatum
• D. Polytrichum

Hint:

Associate different spore dispersal aids with bryophyte groups. Elaters are characteristic of liverworts (like {Pellia}, {Marchantia}). A peristome is characteristic of mosses (like {Funaria}). The censer or salt-shaker mechanism is a feature of mosses with a long seta.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The question asks to identify a bryophyte that uses a "censer mechanism" for spore dispersal. This mechanism involves the capsule, elevated on a stalk (seta), being swayed by the wind, causing spores to be shaken out gradually, much like a censer used for incense or a salt shaker. This is characteristic of many mosses with a well-developed peristome.
Step 2: Detailed Explanation:


Pellia: This is a thalloid liverwort. Its capsule dehisces by splitting into four valves, and spore dispersal is aided by hygroscopic movements of elaters mixed with the spores. It does not have a censer mechanism.

Funaria: This is a common moss with a long, flexible seta and a complex capsule with a ring of tooth-like structures called the peristome. The hygroscopic movement of these teeth (opening in dry conditions, closing in wet) regulates spore release. When the wind shakes the capsule, spores are peppered out through the peristome, which is a classic example of the censer mechanism.

Pogonatum and Polytrichum: These mosses also have a dispersal mechanism where spores are shaken out. However, their capsule opening is covered by a membrane called an epiphragm, and spores escape through pores between the epiphragm and the peristome. This is often called a "pepper-pot" mechanism, which is a type of censer mechanism. However, {Funaria} with its elaborate hygroscopic peristome is the most widely cited and classic example of the censer mechanism in textbooks.

Step 3: Final Answer:
Among the given options, {Funaria} is the best and most classic example of a moss exhibiting the censer mechanism for spore dispersal.