Elaters are absent in:

Question

Accepted Answer

The correct option is 3: Anthoceros

Elaters are specialized, sterile, hygroscopic cells found within the sporangium (capsule) of certain bryophytes, primarily serving to aid in the dispersal of spores by twisting and untwisting in response to changes in humidity. The plant genus *Anthoceros* belongs to the division Anthocerotophyta, commonly known as the Hornworts. Hornworts are distinct from the true Liverworts (Marchantiophyta) and Mosses (Bryophyta) due to their unique sporophyte structure, which resembles a small horn. While the sporophyte of *Anthoceros* does contain sterile cells mixed with the spores, these structures are multicellular, sometimes branched, and crucially, they typically lack the distinct spiral thickening characteristic of **true elaters** found in liverworts. Therefore, these sterile cells are correctly termed **pseudoelaters** (false elaters), which perform the same function of spore dispersal but are structurally different. The absence of the classic, single-celled, spirally-thickened true elaters makes *Anthoceros* the correct answer.

The incorrect option is 1: Marchantia

*Marchantia* is a well-known genus of Liverworts, belonging to the class Marchantiopsida. The sporophyte of *Marchantia* is structurally complex and contains numerous **true elaters** mixed among the spores inside its capsule. These true elaters are characteristically single, elongated, spindle-shaped cells. They possess two distinct spiral bands of thickening on their walls, which are highly hygroscopic. This hygroscopic nature allows the true elaters to twist and untwist upon drying, helping to forcibly fling or release the spores from the open capsule. Thus, elaters are definitively present in *Marchantia*, making this option incorrect.

The incorrect option is 2: Riccia

*Riccia* is considered one of the simplest genera of Liverworts, also falling under the class Marchantiopsida. Although the sporophyte of *Riccia* is extremely rudimentary—often embedded within the thallus and lacking a stalk (seta)—the characteristic **true elaters** are still considered to be present, though they are often reduced, simplified, or highly ephemeral compared to those in more complex liverworts like *Marchantia*. The spores and true elaters develop together inside the capsule, and dispersal occurs only when the surrounding gametophyte tissue decays. Since the sporophyte develops structures classified as true elaters, the statement that elaters are absent in *Riccia* is incorrect.

The incorrect option is 4: Funaria

*Funaria*, commonly known as the cord moss, belongs to the class Bryopsida, which encompasses the true Mosses. Mosses do not produce elaters or pseudoelaters for spore dispersal. Instead, the spore capsule of *Funaria* possesses a highly evolved and complex mechanism for spore release involving a ring of hygroscopic teeth called the **peristome**. The peristome opens in dry conditions and closes in moist conditions, regulating the slow and steady release of spores. Therefore, while elaters are absent in *Funaria*, this genus is incorrect because the question is designed to test the technical distinction between the accessory dispersal structures of Liverworts (true elaters) and Hornworts (pseudoelaters).