Question

Which of the following is called “Adder’s tongue fern”?
A. Cyathea
B. Marsilea
C. Ophioglossum
D. Adiantum

Answer 1

Hint: It is an unusual fern that grows on grasslands, hillsides, woodland, or dunes. They have a spore-bearing stalk that resembles a snake’s tongue. It spends most of the time of its life cycle below ground as a rhizome.

Complete answer: Ophioglossum is an epiphytic growing fern. It is also known as Adder’s tongue. Most of the species grow on rotten parts of trees and exhibit saprophytic nature. The plant body is short, erect, and has a tuberous rhizome that exhibits a radial symmetry. The branching in rhizomes can be dichotomous or lateral. The rhizome has several adventitious roots and its leaves are amphistomatic. Vascular bundles are collateral with endarch xylem and the bundle sheath is absent. This genus has the highest number of chromosomes in all the genus of the plant kingdom. The number of chromosomes present in the meiotic mother cell is about 1260, which undergoes meiosis. Adders-tongues are so-called because the spore-bearing stalk is thought to resemble a snake's tongue. In this genus, plants have undivided leaf blades with netted venation, which leads to the formation of a leaf stalk, terminating into sporangia.
Hence, the correct answer is option C.

Note: Ophioglossum has the most primitive resemblance to the ancestors of the ferns. They do not show circinate vernation as others. They are usually anchored to the soil by some adventitious roots that arise from the rhizome and they do not have root hairs.